For me that's the case.
Ending should be good enough and if a series ruin that, I just can't bring myself to give it a good rating. What about you guys?
I'll definitely rate it lower than I would have otherwise, but it won't necessarily ruin the entire experience for me. Good endings are also relative to the person's tastes. Some love a dramatic ending where a lot of good character die, while others want everyone to survive. Same with ships, most want x character to end up with x character. That not happening can be a bad ending. A lot of people still think the Naruto x Hinata pairing ruined the show.