It's psychology. The last moments of an experience colour your memory of the entire experience, and you rememeber that when you think of it. Nothing about being jouvenile or entitled.
The devs expanding the ending is bad because they're basically polishing a turd. I'd rather they not waste the money and effort expanding a terrible ending, just leave it be. That's not whining that's just an opinion. All the things that make the ending a comple asspull non-sequiter (it's not a case of deus ex machina, that implies it somehow progresses the plot instead of just stopping it dead) are still there. It doesn't help that Bioware seem to think people dislike the ending because it's sad, rather than admitting that it's just terrible from every possible way of looking at it.
Pretty much everyone who played the game thought the ending was bad without reading comments. I dunno where you got that from? I doubt people were going "oh this ending isn't that bad, what, someone else didn't enjoy it? I'll donate money to charity to get it changed then!" But whatever, you seem pretty determined that people who don't like the ending are doing it for some reason other than the ending being a steaming pile.
Also from the escapist article you posted:
Because if it's established that the creators of a story can be pressured by constant browbeating by the audience, then the sanctity of the creator's original intention is made meaningless. The series will effectively have no ending, just a big gap with the words "Audience: Fill In Your Preferred Ending Here".
The above is the opinion of someone who doesn't understand what they're talking about. Does Sherlock Holmes have no ending because he was brought back from the dead after fan outcry? Not to mention the series allready HAS no ending, just a last minute checkovs gun that was never set up in any of the previous 2.9 games. The gaming medias response to this has been the most laughable and telling part of the whole debacle. Calling gamers entitled, whiney, crybabies, etc for having the temerity to ask for a satisfying, logical, ending. To be as bold to say the nonsense drivel isn't acceptable based on the fact that the games creators were bold-faced lying about what the ending would be days before the game released. It's not even the first time a games ending has been changed because the fans weren't happy, but somehow the sky is falling because in an industry entirely focused on customer experience, people are catering to their customers!