I have to admit, the primary reason I dislike tabs is because most of the time I find tabs in a file, they're mixed in with spaces. So you get inconsistent indentation, based on tab widths. I've also seen too many instances of tabs in intra-line alignment, as you mentioned. Depending on tab widths, the columns may or may not line up.

Since I've seen more misuses of tabs than decent uses of tabs, it's pretty easy to pigeonhole them into the "bad style" camp. It's really a very mild dislike, to tell the truth.

And personally I prefer a 4 space indent for real code (i.e., code in my editor) but often I'll drop that to a 2 space indent when posting code online.