I think it can if it's either:
A) Enough of a stinker that it's actually kind of horrid. Because now whenever you think of the show you think of that (which isn't true of a one-off bad episode, generally).
or
B) Recontextualizes the entire show in a really annoying or stupid way.
The main reason I think people object to the nuBSG ending/last season is that it does B. It takes a show that had vague religious allusions, but was fundamentally a pretty straightforward SF series, and the ending recontextualizes it a very vague-yet-annoying faux-religious, faux-scientific way, turning it from somewhat towards the harder end of sci-fi (for the most part) to essentially pure fantasy. Had the show always been fantasy I don't think an ending like that would have been remotely as off-putting. The ending also features characters acting very well... out of character.
I mean, pretty much every reality TV show by that logic, even the few I like.
Actually though an awful lot would genuinely have been better with only one season - Big Brother springs immediately to mind.
I mean, there is a very clear point when it got bad, which is about/after S10.
It's pretty widely agreed (nothing is agreed by everyone, not even the colour of the sky):
I know I kept watching past that for a year or three, but it was noticeable that even "okay" episodes were thin on the ground after that, and you might get one "good" one per season - and zero "classics". In fact as far as I know, there hasn't been a single like classic-tier Simpsons episode in the last 15 years, maybe more like 25.
And believe me I've asked! In the post-pandemic I really wanted some new Simpsons. I tried just watching it, but it was like, dreadful. Unwatchable. But I figured with over 20 years of episodes I hadn't seen, there had to be some good ones. I looked for guides, and asked on forums and Reddit and just no-one had any episodes after the early 2000s that they recommended except some Treehouse of Horrors (for whatever reasons, a few more recent ones of those have worked).
I was actually shocked. I expected to be bombarded with lists of episodes that people were just too snobby to watch. I expected people to have bunches of favourite episodes from the last 20 years.
But they didn't. Not even the people who were still watching it. It was weird, like profoundly weird to me. How do you watch a show for 30 years and only have favourite episodes from like the first 10? Which is what I was getting told, again, by people who were still watching it! Talk about a living death!