Well, why do some people like to read the same book many times or watch the same movie more than once? 
I play with same character and same choices multiple times. It's a good story and I want to experience it more than once. I currently have only two different World States which means two characters per/ DA-game. I play the same characters over and over again because I enjoy it. There's probably lots of content I haven't seen because of this... but I'm in no hurry to see all that the game has to offer me. There'll be time to make new characters in the distant future... and it's nice to know that the game will still have something new to offer me then. Right now I want to enjoy my current characters.
I suppose I can wrap my head around it a bit then. Before I had a computer I had a Sega and (later) PS1 and played games like Phantasy Star 3/4 and FF8 over and over again delightedly. Not sure I can go back to playing console games like that, but I should think it'd be fun if I had portable versions of these to tote to doctor's offices and other places when you have long waits with nothing else to do.
Since discovering Bioware (with Baldurs gate 2) I tend to prefer a story that's more fluid, with a little more player agency. Origins was especially so. While it can be argued you arrive at the end with the same result (bad guys routed, nation saved), there were many different routes you could go about it, following the parameters of the narrative.
While there are some movies (or books) I can watch (or read) more than once, there are others I'm quite content to see once, shelf it for years and pull it out after I've forgotten most of what happened and can enjoy it again as if watching it for the first time. It even helps when you're a little bit older and don't recall things like you used to.
One particular book comes to mind that I have read several times in the over 50 years I've been on this earth that I purchased when I was in high school. I haven't picked it up in at least a decade but I imagine I will read it again at least once or twice more before I depart this earth.
One gets no choice in books or movies, but you do in Bioware games to do things differently, or see things from a different character perspective. And I prefer some variety to my gaming. My choices may mirror in some runs others, but if I know I'll have limited runs (such as the original post I quoted) I try to get as much different perspective as I can so I can see as much as I can. Where I had some 3 dozen runs in Origins, I suspect with the size of Inquisition, I will be lucky to finish a half dozen at most.