Finished “I am legend” and confused

First of I want to say that it’s a great book. Enjoyed it for the most part. I get the hype (and followed disappointment) of the movie.

I was left a little confused by the ending. From my understanding the book only spans 3 years. Why then did everyone think Robert was the freak? They should know that he was the normal one and they are diseased. I would understand being fascinated and even turning him into a lab rat of some sort. But they are straight up afraid of him.

If it had been a couple decades or so and people grew more accustomed to their life then maybe it would make more sense. I know he was “killing” them but it wasn’t like he was raiding vampire camps and slaughtering whole communities.

Even if he killed a handful a day, they should’ve reached out sooner and adapted him into their community or at least told him “hey some of us actually aren’t murderous blood thirsty monsters anymore. Please stop killing us.”

Overall the book was great. Very sad and I felt for him through the whole book. But I think he could’ve been a different kind of legend. One where they think of him as the LAST human. The thing everyone used to be. Not one where they’re scared of him and think he’s gonna sneak in and kill them during the day.