Yes I think this whole theme about not giving up your dream, fit for the ending! Like Izuku from the start always wanted to be a hero, he did settled to become a teacher there but if he has a chance to become a hero again why the heck he won't take it??? (Beside most of UA teacher also still a hero anyway) This guy is literally the one that trying to register to UA while he's quirkless, his dream from the start is nearly impossible so ofc he gonna grab a chance of becoming a hero again. It's like up with how All Might tell Izuku he can be a hero and how Izuku then tell then kid at the end that he too can be a hero, it's poetic and I think despite the flaw the theme of the story stay very firmly! Also I can see how Izuku response to the chance differently from the start and this end :D
I'm gonna go out on a limb here. Most people who didn't like the ending, probably didn't read the manga at all. This story, is so much more than just being a #1 hero. It's about finding connections, even when you're different. It's about following your dreams, even when they're impossible. It's about finding friends and people to lean on when you are at your lowest.
The ending, is good, could it be better? Yes. Was I hoping for him to become a hero? Absolutely! But it's more than just being powerful and kicking butt. If you wanted that, watch season 6, where Izuku is a vigilante.