I like Steam enough that I buy the good majority of my games through them. If you do not like the software don't use it, they are not forcing you to buy your games through them go to Best Buy and get your games there, or D2D, or Amazon, or any of the other vendors.
As far as the download vs install speed it is a wash for me. 30 minutes to drive to best buy, 15 minutes in the store, 30 minutes to drive home, 15 to install. Versus a download and install on a 10mb connection that I just let download and walk away. Plus I save gas and they often preload new games a few days before release basically making it an install disk minus all the driving. There is also no shipping or handling, I don't have to worry about install disks or game keys getting lost.
Steam is convenient without being overly obtrusive, pretty decent service if you ask me.