ton's of people die everyday.I bet you some of them are biologist's.How many times do you cry about them?The only reason you know steve irwin exist's is because he act's like an idiot.He did crazy things that could have got him killed.Then he got himself killed.
Maybe because Steve Irwin was a TV personality that people could see what he was really like. As for those biologists, we don't know them, or what they're like, so it's hard to care as much for them as we would for Steve. Also, Steve was killed in an accident completely unrelated to the dangers of his Croc Hunter job, he was killed by something that your chances of dying from it are less than getting stuck by lightning, or ran over by a car in water.