8) Hidden menus and mystery meat.
Google Maps is the prototype example. In the first or second iterations some years ago, Google Maps was very nice. Menus and functions used to be obvious and intuitive. They've hidden more and more things behind cryptic icons or that only show up on mouseover. I'm sure I could read up on it and figure it all out, but I use it so rarely that it's not worth my effort. Alternatives such as Mapquest are easier to use, and for occasional things like printing directions they're adequate (although Mapquest is also moving in the Google direction).
Just 2 days ago I needed some custom directions, because a road where I wanted to go was closed by construction making the GPS useless. I tried to use Google maps and futzed around until I sort of had the route I wanted on the screen, but when I tried to print only a small portion was shown and the rest chopped off. By trial and error, I kept zooming out until it fit the printer page, but then the street names became suppressed because I zoomed out too far. After about 10 minutes I gave up and used Mapquest.
(I now remember that the previous time I used Google Maps a few months ago I also gave up on printing directly and instead captured a screen shot and printed that! I forgot about that trick 2 days ago.)
And while I'm on a Google rant, they used to have links to to translate, books, etc. on the main page, and now there's nothing. I have no idea how people find these anymore (I have bookmarks for them). Well, I guess they can Google for "Google translate", but you have to know that it even exists before you can do that.