You are saying this as if you cannot download videos and view them on an iOS device from any other source. I believe it is possible to just download a video and start watching. How does the iTunes software help to make that process better? Also many people do not have an iOS product.
The iTunes software sucks quite badly. Don't get me started.
However, the end-user experience for downloading videos from iTunesU and playing it on an iOS is excellent. It is almost a one-click experience. This is just my opinion as a user.
I'm curious, on a vanilla iOS device, what application would you use to download a video on a website and have it cache onto your device?
I agree that if you don't have an iOS device, this doesn't work.
Well, guess we should all go buy iOS devices, so we can have a great one-click experience watching lectures produced by public universities that are paid for by taxpayer dollars and ought to be freely accessible.
(Sorry if I'm rubbing it in too hard, you've been very gracious in this discussion.)
That said, I'm a big fan of iTunesU. I like the ability to download courses on my iOS devices and listening to the lectures on trains or at the gym. Also, they must save a lot on bandwidth by letting people download the videos (I go through the lectures a couple of times at least).