I really, really tried to like Ben, but despite all my efforts, it was impossible. Yet still, I tried to be as neutral with him as possible.
The situation with bandits and Carley forced me to spend a lot of time wanting this kid dead, and I was even somewhat disappointed when I couldn't kill him at the train. As the time passed though, I managed to forget about his stupidity.
However, when Ben asked me to let him go, I did so. Not because I wanted him dead, not anymore, but because it was more or less a good way for him to go, at least trying or pretending to save all the group by sacrificing himself. In other words, he went out in style, more or less.
In that particular scene, I wasn't sad and I wasn't sorry for him - every action may and will have consequences, and you have to face them, no matter how old or stupid or scared you are.
Later on, I've seen a playthrough with "saved" Ben, and I have to admit that him dying with Kenny scene was much more emotional and touching, but again, not because of Ben, but mostly 'cause of Kenny sacrificing himself ( in a rather unreasonable manner ).
Yes, Ben was just a kid, but remember what Chuck said to Lee. There are no more "too young" or "too old", no "girls or boys around".
You're either capable and alive or not capable and dead.
ˇPrepararse para los problemas!
ˇY mas vale que teman!