I think the inclusion of the scroll wheel on modern mice helped fuel this trend. Scrolling was a lot more onerous when you only had 2 (or 1!) button mice, and

I think the inclusion of the scroll wheel on modern mice helped fuel this trend. Scrolling was a lot more onerous when you only had 2 (or 1!) button mice, and you had to actually go navigate to the scrollbar in order to scroll (or switch to your keyboard and use the page up/down keys). The other thing in this vein that is annoying is when scroll bars are so small users don't notice the content in the pane they're viewing can scroll, and will then claim the content isn't there. It is -- you just have to scroll for it. But you can hardly be blamed for not knowing that, because some moron decided to play hide and seek with the content.