About that ME3 MP fiasco... I may have selective amnesia here, but this is how I remember it went down. BioWare said MP was not needed to get all the endings. After playing the SP, forum members pointed out that was not the case, that the EMS scores for each mission/quest without MP did not add up to enough to get the third ending. BioWare devs came on the forums, saying they were quite sure that MP was not needed. Forumites protested. BioWare then went back and checked their numbers and admitted their mistake. And fixed it.
What I took from this, as I assume people are not liars or idiots, particularly on something as easy to disprove, is that BioWare made an unintentional mistake. A mistake that created a huge blow-up. A pretty embarrassing mistake as BioWare first released a lengthy statement confirming MP was not needed when the forum was saying it was. So I am not sure why anyone would assume that BioWare would make the same mistake twice. Or suddenly shift gears and decide to tie MP to the SP campaign, when that was, according to them, never their intent, even for ME3.
Based on this, and until proof of the contrary, I must admit that I fail to understand how some people can be so extremely opposed to optional, free content. The "taking away resources" argument has been disproved ad nauseam. If you don't want MP, don't play it. Simple as that.