"I really can't see what it offers that a powerful computer hooked up to your TV can't"

That's just the point. I do not want to have to connect my TV to my computer. I want to plug my television in, i want to sit on my couch, and i only want to have to think about what buttons to press on my remote. It's called simplicity.

"It Just Works..."
- An extremely powerful and often overlooked notion

"...are we actually turning into useful idiots keeping the arch-enemy strong and healthy..."

I don't think you understand. I do not pay for the songs i download over P2P. They are free. By downloading for free, rather than paying, i am actually hurting "the arch-enemy".

As a result of my download, the torrent file's ranking will increase on the "Top 100" list. By freely downloading a song, i have dealt not only the initial blow to "the arch-enemy" (as it will not be receiving any money from me), I have also dealt an even greater blow, by promoting the song to others, who like me, will not be paying "the arch-enemy" for their consumption.

Yes downloading popular music over P2P networks will promote it. However under the majority of circumstances it's only promoting it to people who will not be paying for it.