When I was in USAF, the pilots said, "When your fear of staying in the plane exceeds your fear of the ejection system, it's time to eject." That wasn't really a joke.
I've seen comparisons of American vs. Russian ejector seats. It appears that Russian seats are better designed to protect the pilot from injury while ejecting. The issue of ejector seats has been used to support the idea that pilot comfort and safety is a low priority for American designers.
Soviet designs tend to be more artisanal. Sometimes it gives them oxygen-rich rocket engines and better engineered ejection seats, other times it malfunctions and flip over ISS or send a space probe back down to earth by accidentally cryogenically freezing out a computer.
Since even a successful ejection will hurt you due to the immense forces at play (an explosion will push you out the plane) even in the best case, and crush you, if something goes wrong, no wonder that joke is for real.
