No, I wouldn't say it's bad. Modesty is a valued quality but not everyone is modest and there's nothing wrong with that.

The difference between someone who is and isn't a hero, in my honest opinion, is why they do good deed. Doing them because you want to be thought of as a hero and not because you truly care about the person/people/animals you're helping is different than doing them because you truly want to help the person/people/animals.

Nevertheless, in either case, someone was saved. So, it certainly isn't a bad thing despite the motives. Hero is kind of a subjective term. But I think the whole 'true heroes are always modest' thing is wrong. Many of them are. But certainly there are people who do good things because they truly care yet want some recognition for doing good things.