- Collapsed comment threads. Nothing against Dreamwidth; I have always, always hated them, no matter where they might pop up. Knowing I'll have to click on one thing to "open" another that should already be on the page (and in fact, is on the page, just in a hidden form) is the online equivalent of chalk across a chalkboard.
- Expanding comment threads. Try this experiment on anything less than a blazing-fast connection: open this comment thread in a new tab. If you use Firefox, you can install this add-on to check page-load time (or you can just use Opera). Now go back to that thread and "expand" it (which will not exactly happen; you'll expand only part of it, then keep expanding it as you work your way down the thread). Check page-load time again. Which way loads comments faster? If you don't have a timer add-on, which way seems to load them faster? Now imagine how long it must take people on slow, unsteady (wifi/3G/dial-up) connections to use expanders.
- Being informed by the Intertubes that there's Greasemonkey scripts to save you all that comment expansion. Using scripts might've made sense when the only sites with collapsed threads were LJ and, well...LJ? Now everyone has them, from LJ to Dreamwidth to Facebook (and FB's implementation is even slower) to The New York Times, so you need scripts for increasingly large swaths of the Internet. Even worse, scripts (especially if you use a lot of them) can slow page loads as much as waiting for threads to expand, so what exactly do you gain?
- Being unable to show anything on Dreamwidth's default view besides unexpanded comment threads. DW strikes me as more user-friendly than LJ and its clones, so as a user, I would love to see the option to keep comment threads expanded by default across the site.
- "Flattened" comment pages. Instead of threads looking like threads, they become shapeless and without form so you have no idea what's going on. In Flattened Comment Dimension, you rely on clues like "Re: DIAF already", "In response to Jerkof11" and the almighty blockquote to figure out who's replying to who. Why not just chuck comments into a blender and display the output? Same difference.
- Facebook design. The chilling insistence upon one blue and white background, one tiny, greyish, and nearly illegible font, one Timeline, and one slowly expandable and completely un-navigatable comment thread is how I envision every website will look once Communist China takes over. Which scares the crap out of me.
- Photobucket. Page load times there will make you want to move to South Korea to speed things up by even a few seconds. I've never seen anything, and I do mean anything, like it. I would delete both my accounts if they hadn't gained over one billion of my pictures long before the site got so slow, and if only Photobucket would offer an export tool to help me get them out of there.
- @font-face. I've been playing with imported fonts for years but I still can't find much use for them. The best examples I've seen can make sites look marginally better, but for that one bit of splashiness we all pay by way of slower page loads and flashing text. Computers should come with a better and wider range of fonts - not slow down to load fonts from a far-off website. It's the worst implementation of a good idea I've ever seen.
- Google Plus. I have just one thing against it - besides this (but since I don't use it, I don't really care what they put everyone else through) - that Google took their ideas for Circles and filters from our very own Dreamwidth. I didn't guess where those ideas came from until Google tried to hire denise, this site's owner, shortly before rolling G+ out to the masses.