The reason is that using technology properly is hard, time consuming, and can detract from classroom teaching. A simple example: put up too many slides, and students concentrate on them and ignore what I'm saying. Put the whole lecture on those slides (and put them online) and students won't attend class. Students rightfully understand that there's no point attending unless there's something to be gained by doing so. Of course, what they miss is that skipping removes the important interactive component to learning that they get in the lecture setting, at least for small to mid-sized classes. Now, you can replicate some of that interactivity online. There are a lot of techniques: online discussion groups, student created wikis, that sort of thing. They work, although not as well as class discussion, in part because students can easily game whatever scheme you put into place to make them participate in a way that can't in class. They are also hugely time consuming to use. If I'm mandating using a discussion group, I or the TAs have to moderate it and keep track of participation quality. Moodle, the courseware package we use, can count participation events, but that tells you little about the quality of a student's participation. I think, for a fairly traditional lecture course or seminar the benefits of using courseware are comparatively small and the costs in my time and in TA time just too great to be worth it. I think there is an important place for it where you do away with the traditional lecture component, but I'm not willing to go that route, at least not yet.
I do use Moodle for online readings, communication with students, posting the syllabus and class slides, receiving assignments, and returning grades and comments. I also usually turn on the student forums, for those that like to use them. All of this is useful stuff, but it just replicates things that we could do using paper and bulletin boards. Heck, my powerpoint slides could just as well be presented using an overhead projector.
Today, musicians can record with (nearly) the same quality in their house as they can in a major studio.
Just to be clear: they can't. The recording equipment has become much cheaper, but the the cost of making an acoustically designed studio has not. Nor has the cost of hiring an experienced engineer for the recording. I love what can be done with today's PC-based recording equipment, but a real studio is still a real studio and a garage is still a garage, even if the tracks ultimately end up on a Mac either way.