I just gave some thought to why it bothers me and I actually think some of it might be because they trigger a kind of "oh shit a 'search bar' add-on, kill it with fire!" reflex from the bad ol' days of most computers being full of malware and spyware (now the OS and most programs are spyware, so... progress?).
Of course the big ones are simply obnoxious wastes of space, and any that have a drop shadow on the content bother me for what seem like obvious reasons, but even the small ones bug me and I think that might be why.
[EDIT] That's just for the static ones—the ones that pop in and out based on scroll behavior are one of the worst design trends in the entire history of the Web, which is saying something, and are in an angry-making category all their own.
Of course the big ones are simply obnoxious wastes of space, and any that have a drop shadow on the content bother me for what seem like obvious reasons, but even the small ones bug me and I think that might be why.
[EDIT] That's just for the static ones—the ones that pop in and out based on scroll behavior are one of the worst design trends in the entire history of the Web, which is saying something, and are in an angry-making category all their own.