I do it partly to make it stand out, and partly to emphasize html tags. There isn't really a strong reason that I do it, though, I just happen to like how it looks. Is that so bad?
Yes, tags that I close I think I always close in the opposite order. But I don't close all tags, like for instance <br>. I dislike how "<br />" looks, so I generally just use "<br>" and nothing more.