My wife works at our local PBS station and I think she would encourage dialog from the community. If they are not showing something, call them and let them know.
Obviously, try to be as polite as possible, but state your claim.
PBS relies on "viewers like you", so your opinions and comments really do make a difference.
I would also encourage you to support your local PBS station with a monetary gift.

PBS puts food on our table.

I had to throw that in there.
Again, do voice your concerns, but try to be as nice as you can.

All you have to do is mention that you'll have to reconsider your contribution to the station during pledge...that will perk their ears up.
Cheers,
PBM
"We paced ourselves and we didn't rush through it and we tried to be as creative as our collective minds would let us be over some course of time instead of just trying to rush through a record"
Wishlist Foundation: http://wishlistfoundation.org