As to movies with its cinematography, as a picture with its 1000 words, a demo that tests the limits of a machine, incorporate a 3D graphics engine in which no Amiga was capable of by thought, and bring out awesome "visualaztions" and kick*ss music, I'd say it's worth it. The community thinks it's just a waste of time--until they either see the video or install the demo and run themselves. I do that, and most of the demos are awesome. They captivate, they entertain (esp. the mature content believe it or not), they fascinate. And, in a way, it keeps hackers from sending viruses. :-P
:-)
I've seen classic Amiga demos and yet wonder "OK, I know the pc and do that, but how is it possible that my Amiga can do it?!?!?!" Other cases you look at it in a state of awe (No, I'm drug-free forever). I rather have my amiga "show some talent" and wonder how they won awards at a pc-demo competition a few years back?
BTW, if you have WinAmp5 installed, take a look at Demoscene TV under "Internet TV" and see how cool those Amiga demos are.