Ask HN: Carriers and OEMs, why the bloatware and the stickers?

I'm very curious to why every large non-Apple PC OEM has stickers and bloatware all over their products. If they spent less time (and money) on those extra goodies that nobody wants, wouldn't they better off focusing on the core of their business -- making good computers, period -- while annoying their customers less?

Similarly, with Android phone makers who create their own custom versions of Android (and bundle apps that you can't uninstall), why not instead just use the stock OS and work on making the newest builds available as soon as possible, like the Nexus One?

It just baffles me when the way to winning customers' hearts is so clear, these guys spend the extra time and the effort to do the opposite. Am I missing something?