I have a habit to select some text in a page when I'm reading it. And I hate websites that trying to immediately interact with me when I'm selecting a text (usually it's "fix a typo" or something similar).
Hate is a pretty strong word and kind of irrational.
Textselection was probably not intended as reading aid, so don't be disappointed if it is abused to actually, you know, select text to do something with it.
I agree, user scripts can be presumptuous and what not. I used to read with text selection the same way, and even reacted repulsed at advertisement hover pop-ups. But somehow I don't do it anymore, so I don't care as much.
