Yes, I still use BrickShelf.
Why? I have yet to find another picture hosting service that provides as nice navigation through sets of pictures. The folder organization, the browsing through a series of pictures with relatively little clutter.
I'm sure there are lots of advantages of using the other services, but BrickShelf works, I've got all my digital pictures there, and I like the interface.
I completely understand your point. I too probably would still be there for those same reasons, except...the regular worry that at any given point, without warning, the plug will be pulled on brickshelf...well I backed up all of those pictures and any of the ones I didn't want to lose of others...and have moved to flickr. I left my brickshelf photos in place, and every so often go back and cringe at my stuff there, but hey we all have moc's like that..so I'm proud of it.
I think that is why a lot of people did leave. The time when brickshelf was shut down during the summer is not easy to forget.
Plus there is the added pleasure people get about comments and groups and discussions that flickr has. Some people really like those and think brickshelf is very out of date.
But it is a personal choice and I really think people's choices should be respected.