For the first question I never hated the endings, but then again I played all 3 games in the same year as opposed to people who were around since the release of ME1. I didn't discover how much I truly loved Mass Effect until a few months after ME3's release during a re-playthrough of ME2 which helped me during a bad time in my life. I only dislike how ME went with such a cliche motive for the Reapers, since it always seemed to be above your normal cliches.
In regards to the second question you're never going to get a real answer. The people who are self-entitled and/or think their ideas are worth listening to are going to pretend like Bioware was their birth parent who abandoned them in an alley. More reasonable people will say that they poke their heads in from time to time.
The fact is that BSN is a horrible place to get feedback from and I think Bioware has realized this. The people who eagerly await ever game conference and line up for those Bioware panels, the people who post on twitter and send them mail about how awesome their games are the ones they pay attention to most, as they should. They also listen to reasonable complaints like lack of exploration, which is why they're bringing back the Mako. They also seem to realize that Mass Effect works best when its focused on the characters and not machine god indestructible entities that are cliched, going by their claims of ME:N being a more personal story. One could also argue that if the only reason someone comes to BSN is to have Bioware read their posts, they are doing it wrong and setting themselves up for disappointment. These forums are mainly about fans interacting with fans.
Bioware just can't listen and try to please every single person with an idea, and some people really seem to get butthurt about it, crying that they never listen. You can see it in this very topic for a couple of posts. Most likely Bioware has their own vision for the game, and listen to the ideas that best fit within their vision. Bioware games have never ever ever been constructed by the vision of the fans. The fact Bioware once tried to advertize that fans are creators of the ME story as much of the developers was a HORRIBLE idea that they will never stop paying the price of (because some guy who spends 60$ to sit in a chair and do nothing for weeks on end is of the same qualifications as the people who pour blood, sweat and tears, as well as millions of dollars into every aspect of development from writing to artwork to gameplay. At least some people seem to have thought).
Well to be perfectly honest, my main reason for coming here was to voice an opinion, because unlike Bethesda and Gearbox who let you send them messages/emails that they might reply to, Bioware says they don't have enough people for it, and instead leave their players to interact with each other. if I want to tell Bioware and or it's employees something or ask a question, I have to go on twitter, cut it down to 140 letters, make it public, and hope they respond.
I'm aware that there is little to no chance of anything coming from telling them, but I wanted to for a little peace of mind. Honestly, other than from Bungie, I have never felt as ignored by a studio. I understand you can't answer x amount of emails in a short time, but I don't think anyone would mind if you answered them one at a time based on when they were sent, or even sent back an email with a message saying that it's been read or something when an employee is done reading it.
Honestly, this game's ending already depresses me enough, but after awhile of being depressed about that the whole story pretty much unravels for most of ME3 once you think about it and learn more about it online. Honestly, in my opinion, Bioware screwed up big with ME3's ending. The fact that they told VOs like Mark Meer that they might have to voice new endings shows that they didn't even have confidence in their own ending. None of our choices mattered, if someone played enough Multiplayer then pretty much nothing mattered at all.
Supposedly, they made the EC for clarification, which was basically them trying to say "No, no, you didn't kill everyone! see, the Mass Relays don't explode, and your crew doesn't starve!" However, the story is still full of plot holes, and the EC only drove the point home that Shepard dying depresses the hell out of your crew.
Throughout the whole Trilogy we were told our choices would matter, that the fans decided the ending as much as the writers, that we wouldn't be choosing A, B, or C. however, we were given exactly that, with choices that were pretty much the same as Deus Ex, even more so with the EC's new refusal ending, which felt like the Devs flipping us off for not liking their endings.
As for the Citadel DLC, they made it to try and give us closure, even though players want closure with individual characters AFTER the ending. Hell, for most people you have to watch your character die, unless you commit genocide right after the DLC.
If the fans raise that much of an uproar, donate that much money to charity, and send you 400 cupcakes just to get your attention, you know something is wrong.
I wasn't really able to voice my displeasure during the initial uproar over the ending, considering I'm most definitely on the younger side of the fanbase. But now that I'm playing the series again after a bunch of disappointing releases, I can't even get myself to start ME3 again.
The ending was so bad people created god knows how many art pieces, memes, stories, and articles about it. A lot of people are only able to barely enjoy it through a half-decent PC mod, convincing themselves to kill EDI and Geth without feeling guilty, writing stories and trying to convince themselves that it's canon, or stopping right before the last battle.
Honestly, ME3 feels like a scar to gaming for me, and I don't know if I want to start a new ME game. I know someone will probably say that one person not buying the game won't matter, and they're right, but I can't help but be disappointed and angry at Bioware and/or EA.