Dante Alighieri wrote:
Why are people so unwilling to use "they" to
mean "he/she"?
Well, to some people it seems ungrammatical, since "they" hasn't been
used as a singular pronoun until very recently, so you end up with the
"wrong" verb tenses. So when you say something like "They fall asleep
as they watch TV," it sounds very much like you're talking about
multiple people.
-Mark