Would you like to have Photoshop or Windows Movie Maker start everytime you run a game?
This is a false equivalency and a rather poor one at that. Steam is DRM - it just so happens to be a DRM that a fair number of people find acceptable. If you don't find it acceptable, no problem! Just stick to a version without DRM - or, just don't support the project at all! I personally refuse to buy the Assassins Creed games, for example, due to the highly intrusive DRM they have had. I find steam drm to be much more palatable - I don't exactly prefer it, but it is something I can live with, that only minimally restricts me.