If the interface doesn't have a low learning curve, they're probably not going to waste time with it. I was at a university that used Blackboard, which would be great if it worked as intended. But, it was slow (sucked for students) and apparently has a terrible interface that professors have to go through (I never heard a positive word from them). As a consequence, I'd guess about 1/3 of my professors didn't use it, 1/3 used it sparingly, and the other third made a graduated use of it with a handful relying on it almost totally. I don't think I had one professor that didn't have to rely on their own website to pick up the slack, and many just said "hey if I have to set up my own website anyway, why bother learning Blackboard on top of that?"