I don't like BBcode because it is just as difficult to use and ugly as HTML, while not actually being HTML, so instead of learning one thing you have to learn two. It has no reason for existing. This is idiotic.
Also, BBcode is only really used by phpbb and its clones. Everywhere else, people use either some sort of simplified markup (wikis and the like) or a subset of HTML (Of the sites I use, Slashdot, LiveJournal, Flickr, and various blogs come to mind).
As for why I don't like PHP, did you read that post I linked? PHP is a mess, and it encourages sloppy coding (in that example, it makes it extraordinarily difficult to write properly secure code). It started out as a quick hack to add a little bit of dynamic content to webpages, and for that, I think it was useful. Then it suddenly wanted to be a Real Programming Language, but ended up as just a big mess.