Oh boy, we've got one of 'those' people here....Ok, fine, I'll bite.
Believe me, when I'm not being serious my posts are really preposterous -- for instance, saying that Refuse should have been the only ending in ME3. I don't think being ambiguous about your level of seriousness is a useful approach on a message board like this. It's hard enough to sort out the real crazy positions from the deliberate nonsense as it is.
............................ 
Ugh....I can't even....just no...
Or they boot it up without NG+ and play it with a different character. And a second different character, and a third. Both ways are replaying.
YES, I wasn't talking about EVERY GOD DAMN gamer on planet Earth, was I? I was talking about a significant number of gamers who DO do exactly what I just described.
There are people who will only likely replay a game if it has NG+. Yes, I know, not everybody is like that, but a hell of a lot of people are. Many people just don't have the time or the patience.
I know this might be a horrendous shock for you, but not everybody is the same, and they're certainly not all like you. I know, craaaazy, right? I can tell from what I've read in your posts so far that you're one of these arrogant people who A) thinks half the world is like you, and the other half aspire to be like you, and B ) enjoy just being difficult and argumentative for its own sake, taking people facetiously literally one minute then ignoring half of what they said the next.
And I wasn't suggesting NG+ is the only way to replay. Nice straw-man fallacy.
Actually, your replies today have made me more confused about the issue than I was. I thought the idea was that the game is more fun at high levels, so you want to start the game at a high level. (Though that still doesn't explain why you need to play it first from a low level -- why not just use a console command, if you've got them, to start at a high level from the get-go.)
Firstly, because I'm not playing on PC, obviously.
Second, that's part of the appeal of NG+. You need to start from a low level to 'earn' your way to the higher level - just using a command or exploit to instantly zap yourself to Level 20 the first time you play, is 'cheating'. I don't want to remove all challenge from a game I'm playing, the first time I play I play legitimately, because that's part of what that game 'is'. But, once I've reached say, Level 20, and completed the game, then yes, going back and playing from the beginning at that level is more 'fun', than just running around the open world in the completed profile, trying to find enemies at lower levels than me. It can be fairly fun, for a while, but doesn't compare to NG+.
But then we have:
So it's about story and doing all the different paths differently? Well, sure, but how does playing the same character help with that?
Because I like the face I spent hours designing. That's 'my' Inquisitor, that's who I see in my head when I think about the game. Just like my Shepard is the same Shepard across all my play throughs - for me, 'my' Shepard is the Shepard of Mass Effect, and I have to remind myself that other people see a totally different visual in their mind's eye when they think of Mass Effect, and that's part of the fun.
Wouldn't the same character do things that are in character for her no matter how many times you use her?
No, 'cause she's got Multiple Personality Disorder..... 
Seriously, you must be freaking unbearable to watch a movie with; "Well, I don't believe this character's actions, because I saw this actor playing a different character in another movie that would never say or do the things this character is doing...."
The face I've designed for my Inquisitor is like an 'actor' playing a role. I want to see what that actor looks like doing the various things the game let's you do. I might play through once being nice, then play through again being kind of a bltch. Then on my third playthrough I might mix it up to get my 'definitive' Inquisitor. I might play through once as an atheist, then again as a 'believer' in the Maker. And in the case of DA: Inquisition, some of the 'choices' are not actually choices at all, such as who becomes Divine, so maybe the eventual Divine in my first playthrough is incongruent with my Inquisitor's character after all.
Or maybe I just regretted some of the choices I made for my Inquisitor the first time round, and would like to replay it getting those choices right without having to start entirely from scratch, doing the same 20+ hours running around collecting shards and delivering herbs. 
Or is it about playing different characters with the same face? Or is it just about blowing through stuff on a second run?
For me, yes. Some people like NG+ for other reasons, but for me, this is the main one; I like to experience the narrative of the game in a more seamless way, without the endless point grinding in between story missions. Some people might scoff at that, I don't care, sue me; I like games with a good story.
I'll play a game with a good story but bad gameplay (ME1, anyone?). I'll only ever play a game with a bad story but great gameplay, if the gameplay is really, really, freaking good (such as Devil May Cry). If it's a straight up toss between a game with good narrative or one with good gameplay, I'll pick narrative every time. ¯\_(ツ)_/¯
If so, isn't that what's Casual is for?
No. Casual is for people who've never played the game but aren't very good at those kind of games. Novices, in other words. I am not a novice, I just don't like spending 20+ hours grinding when I've already done it. Plus, I like to feel that any continual grinding I do is moving me up even further.
Plus, Casual doesn't allow you to 'breeze through' the leveling and grinding so you can just go to through the story missions. All the leveling and grinding is there, it's just slightly easier - so maybe 18+ hours instead of 20+.
Maybe if Dragon Age Inquisition had a 'story mode' like ME3 had, that might do. It'd still suck that we can't import our completed Inquisitor's face, but it would at least be something. However, I just think that in this day and age, a leveling up game that doesn't have NG+ just should not happen any more. There really is no excuse for it.
As you can see, I'm really not getting it.
No, you're really not, and I doubt you ever will. It's like me trying to figure out why some people read Twilight; I just literally DO NOT understand what they are getting out of it, or why they bother. But you know what? I'm not telling them they shouldn't be reading it, and I'm not telling Twilight's publisher that they shouldn't be publishing it, just because I happen to think it's horrendous and a waste of time. I'm sure there's stuff I like that they find equally horrendous (Dragon Age, probably), and that's all good, because it would be boring as hell if we were all the same and liked the same things. ¯\_(ツ)_/¯