I look at it this way. People wanted to bring the movie theatre experience into their homes. To accomplish this, you need more than two speakers. 5.1, and 7.1 systems began popping up to fill this consumer demand. Music wasn't really what brought about 5.1 systems. It was movies.
But now people have 5 speakers in their living rooms and wonder why they heck when listening to music are three of them sitting unused. So then we were brought SACD and DVD-A. Surround sound music! It sounds great (when done properly) and uses our systems to their fullest capacity.
There are plenty of us on these boards that have both 5.1 and 2 channel systems. I have 5.1 in my living room and a 2 channel setup in my bedroom.
I think the reason AV recievers are "pushed" is that like was stated before...with an AV reciever you get the option of both 5.1 movies AND 2 channel music if you desire. With a simple 2 channel integrated amp...you'll never be able to experience a movie soundtrack in 5.1.
