Re: Band members that slow progress in Band development.
I haven't read all the replies above, but what always comes to mind when it's about motivating:
"You can't pull a dead horse over the finish line"
Something like that someone told me once, and it's true. Find yourself some real horses to work with, who will run in the same tempo and do not try to 'waste' energy on people who are not worth it.
I hope it works out for you, and that you find those people with the same vision.