Well, the TTC never got back to me about my earlier complaint but it looks like they were listening to me!
I finally tried taking the Dufferin bus from Bloor yesterday (I've since given up and am doing the 20-minute walk home from Eg West Station instead) and noticed that they have a collector standing at the side door letting people in from there. It's a nice step. Even nicer would be if they didn't assume TTC riders were criminals and gave them the benefit of the doubt, but I guess I shouldn't look a gift horse in the mouth. Thanks TTC.