Been there myself. In fact, I have a diacetyl bomb on tap right now. It is a dumper as far as I am concerned, but I have a number of friends who like it... so, I am keeping it (and preserving my Helles and Pilsner for myself
I do the same from time to time, and I dump anything I don't like/others don't like. I never understood the "I'll never dump a beer" crowd. Hell, I'll dump a marginal beer just to put a new one on tap that I am excited about. (I have 6 on tap generally). When I reflect on my sub par beers, it almost always comes back to a few things - 1.) Getting in a hurry and rushing a beer to tap/through fermentation faster than I should have (I skipped Diacetyl rest on my current D-bomb because I was in a hurry. 2.) Pushing yeast too many generations, thinking I can get by with using old yeast, underpitching lager yeast because I am in a hurry. 3.) Just rushing things in general trying to get too many batches done, too quickly.
I also second what Denny said - from time to time, just really revisit sanitation and switch it up. Once in a while, I'll just take a day and instead of brewing, I will deep dive into my brewroom. Clean it all, use Iodophor instead of Star San, hook my kegs together and pump Iodophor through all of them,replace old tubing, etc.
And, then, go back to a couple "old faithful" recipes to get back on track.
Happens to everyone from time to time.