D Borous
It Wandered In From the Wastes
Eh, I mostly was appealing to the games which I felt were important to me as a whole versus trying to argue the entire industry's disturbing trend to fall back on multiplayer over single player.
But off the top of my head:
Deus Ex: Mankind Divided
Halo
Dead Space 3
Grand Theft Auto V
Homefront
Assassins Creed: Unity
Mass Effect 3's endings were warped by the fact they had a Multiplayer by necessity moment.
Spec Ops: The Line's completely useless one
Battlefront
Knights of the Old Republic to SW: The Old Republic
Marvel Alliance became Marvel Omega
Star Wars: Visceral *
* https://kotaku.com/the-collapse-of-viscerals-ambitious-star-wars-game-1819916152
But yes, I feel micortransactions are a bigger issue but multiplayer has dominated a lot of these.
I'm a big believer in context, and every example sort of has its own story. I don't know the full story in every one, so I'll only give a brief summary of the issue in a few of them:
Dead Space 3: This was a case of executive meddling slowly but surely turning the series from survival horror with action elements into a full on action experience. It weren't multiplayer but co-op and microtransactions that ruined Dead Space, all with the intent of making it appeal to wider audiences so it would sell better, but instead the reversed happened, and now there's no more Dead Space. This video explains the subject in detail: https://www.youtube.com/watch?v=edcBLDNR2Ig&t=609s
Assassin's Creed: Unity: I don't recall multiplayer ever being the bane of contention with this title. It was the blatant case of it being rushed for current systems and suffering a wealth of technical failures for it. Remember Ubisoft was also developing another Assassin's Creed at the same time.
Spec Ops: The Line: Again, it was a case of shoving it in there with the hopes of selling more. In that case, I think i can say that the multiplayer element doesn't tarnish the intent of the singleplayer. Here's another recent video and both modes:
Anyway that's my opinion on a few of them; I could probably write a novella on GTA and Mass Effect apiece but I'll leave it there.