I think it's funny how academia selects people based on their scientific aptitude and research experience and then puts them into positions where they have to spend much of their time teaching (something they may not have the aptitude for and definitely aren't trained to do) and writing grant proposals. The more experience people have, the less time they have to do research (with the exception of a relatively small number of celebrity professors).
With that said, I'm not sure how things could be changed for the better. I'd say that some training in teaching would be good, but I think most academics don't actually want that. Being a TA was already an unwelcome imposition back when I was a grad student, so I wouldn't have wanted to spend more time away from my research to become a better TA.