TL;DR: The sunk cost fallacy. It's the tendency for people to carry on doing something even when abandoning it would be better for us. Because we have invested our time, energy, or other resources, we feel "it would have all been for nothing" if we quit now.
Star Trek in 1966: has a bridge crew containing a black female, Russian man, and faaaabulous Japanese man, each of whom holds the rank of full Lieutenant on their own abundant merits