Two reasons for not using PS express for me:

1. I'm sure I'll mess up sometime and accidentally place a photo in public viewing, at which point, according to the TOS, Adobe gained a perpetual right to use it even if you didn't mean to make it public.

2. There's nothing I really need on there right now. This would be useful for quickly correcting some photo before posting it on the web while you're on the road and don't have a laptop with you. It certainly won't replace PS for real photographic work.

Thus, until Adobe removes this kind of language I don't want to risk my photographs (even though I doubt I'll ever sell any of them).