Simplicity is what people make it, and can't be counted by the number of speakers or the amount of money spent.
As someone said, a good set of headphones and a CD player can outperform multi-thousand dollar systems and can do it far simpler than anything else out there. Hook up an iPod with lossless audio and some headphones and you have days of music listening with great quality.
Yet, audio is an experience to be shared, and home theater and music are two very different beasts. The avid music listener can swear by two channel audio, but completely miss out on the specific enveloping nature of a lossless Blu-ray presentation of 5.1 or 7.1 audio.
For those who just love their music, by all means, set up 2.0 or 2.1 for your specific tastes.
But, for those who love the complete audio/video experience, then simpler and better don't necessarily go hand in hand.
I would say though, that a great deal of the pleasure of home theater comes from the social experience of forums, of going out and listening to different gear at stores and at friend's homes. The knowledge that comes along with seeing how different projectors can look and seeing how good your system really can be.
A system is often only complex once... When it is set up. Once you have run those 8 wires in your room to speakers, and some wires to the display location, you are often done with the hard part. But, it is almost disappointing... the hard part can be the fun part with it. Yes, simply enjoying the audio is great, but for many, it is the audioholics experience to not just enjoy the audio, but every aspect of setting up and configuring a system that uniquely meets our own personal love of audio and video.
2.0 or 9.4? That's not what makes it complex or simple. It's our own personal tastes and influences into our setups which makes it complex and simple, and most of all, enjoyable.