I think that requiring major changes would often preclude the marriage in the first place - although I could see difficulties if one spouse changed during the relationship and wanted the other to change with them…
I think it really depends on the couple and on the habit/view/whatever being changed. I see a lot of room for change on things where you feel yourself that it’s something that needs changing (e.g. a bad habit that might not matter all that much to you on your own, but you’d rather avoid to make things easier for your partner) - but less for things where it’s purely the partner trying to change you.
The poll didn’t say, “Pick which statement you agree with absolutely: (A) Never change anything about yourself in a relationship -or- (B) Always change to accommodate your partner.” The question was which of the options you mostly agree with, and option A says you shouldn’t have to change much, and allows for exceptions. There are some fairly minor things I am willing to bend on for my old man. For example, he’s got some weird thing about keys jangling when he’s asleep; it wakes him up for some reason. I don’t respond with, “I jangle my keys. Deal with it.” If he’s sleeping and I need my keys, I make a point of picking them up noiselessly. I view this as a very minor change that I make in order to avoid being an ass. I do this for a lot of people. As a rule, I don’t think significant changes should be made for the marriage. If the person needs so much reform, why the hell are you with him?
I find myself adjusting my wardrobe choices (which ties, which kinds of casual shirts) toward items that I know my wife finds appealing. She, on the other hand, refuses to wear the catsuit.