No one complains about the back button just because they don't want a way to back out of a page/action/whatever. They complain because the back button is too often unintuitive. It's never "Ugh, I hate it when the back button does precisely what I expect."
If you're going to compare to the web browser, you have to acknowledge how utterly obnoxious it is when some rogue site breaks the back button. Except then you can at least click-and-hold (or equivalent) on the back button to get a drop-down with more history so you can hopefully back out of whatever crappy site you opened.
