Email is 99% for marketing. They all want in on the metrics from places like Steam, often so they don't have to pay steam for their marketing info. Nvidia can start throwing in more AAA games for free if they want to go this route.
For me, its just one more annoying program hoop I have to jump through. If I want it, I can install it. Requiring it for just drivers is insane. There are systems where I am not going to want that nonsense installed.
Also, perhaps the lots of tiny pieces of software issue is from days of yore where you really couldn't or didn't want 5-10 little things running in the background to interfere with your system and game play. Today, most people can afford to run several things in the background with a game given quad+ cores and 8-16GB of ram. Yet we are now seeing games that really favor 8+ GB of ram to run smoothly and requiring quad cores.
I run the least amount of software I need while gaming, to maximize performance. It comes from experience, going back to editing config.sys and autoexe.bat files. These days its just trying to make sure some scanner program or communication program isn't hogging bandwidth, sending popups knocking me out of a game or killing system performance.