That doesn't appear to be the focus. Facebook and Twitter timeline ads will remain, obviously (does anyone actually click on the floating ads on the right of the FB UI), Daring Fireball retains it's very subtle image ad (but, who are we kidding, it's one big Apple ad anyway, amiright?).

It would be ethical to include the ads though.

Annoyances are not always ads. Looking at twitter it's also removing annoying "features" like trending, who to follow, and the extra navigation box from the left column.

'User styles' is a common name for user-applied CSS stylesheets; it's not necessarily about applying styles in the English sense of the word. According to the author, these stylesheets remove some of the clutter, which presumably includes some or all ads.

If this wasn't about removing ads, they would have been reformatted to be beautiful too.

Removing ads is effectively the same as pirating software: You're getting what you want without paying for it.