Spolier: Do not put 'listening to leftists' as your answer, too easy.
With the paracite hangers on of game 'journalists' the first to go, the amount of bleakness from Ubisoft, EA trying to sell itself harder than a crackwhore, we are approaching a point where we may end up with only 3-5 major ones left and a few focused on one title that's been around for decades (eve online, your DOTA games etc).
Doesn't really affect us as I think I'm safe in saying we all have backlogs that can outlast us being on Earth! So why not make this a fun opportunity to go 'you know, if you did this , you wouldn't be begging for money'. Choose whichever companies you want on what you think was a missed opportunity:
EA: Not using their IPs together enough. Seriously how hard would it have been to make a Battlefield game set in the Command and Conquer Red Alert or Tiberium franchise or even do a sports game but in the backdrop of Mass effect. They seemed to be all about processing IPs than using them effectively.
Bethesda: not using an Id engine for Fallout 4. When I played Rage, the story was lackluster but the combat and gameplay was smooth, fun with fantastic visuals. Unless there was a hidden licensing reason, why not use THAT for Fallout 4, that seemed like the perfect engine .
Nintendo: making it too difficult to buy and play older titles so creating a piracy market.
Microsoft: not letting gamers be the one to design their military AR project as they could've probably told you the dumb parts quickly.
Sony: Not embracing Japanese game devs, not leveraging their monopoly on anime with PS+ by doing, for example, free first 3 episodes of a series on Crunchyroll if you have PS+. Also on Crunchyroll, just put an adults only section for uncensored anime, have it behind a paywall of some small fee and a SECOND password and you'll probably get a lot more subscribers.
There's more I could mention like Ubisoft, Rockstar, CD projekt etc but gone on too long and let this be a collective 'I would've done this' thread.
Chasing photorealism at the cost of everything else. Crysis started this trend and pretty much every game since has been making only incremental improvements to graphics. Gameplay, however, has suffered.
Technical bloat. So many games nowadays are multiple 10s, if not 100s of GBs in size, with multi GB patches. For people with bad internet connections, this is incredibly tedious to suffer through.
Desperatley trying to seek approval and validation from TV and Movies. This was already covered in this thread, but it bears repeating. I'm sure it's easier to count the number of people in gaming not here because they couldn't cut it in Hollywood.
Lack of professionalism. With how important public image and marketing is to certain types and their influence in the wider culture, I want to know who's teaching these people to be openly antagonistic to their customer base.
I can think of 3 individuals off the top of my head, there are others of course but those three were at the heart of the outrage, grifting shamelessly