That's fine as long as they give you time to notice them. If they simply indicate right 1 second before they turn, what are you to do?
Both that and the French rule are simply enforcements of politeness. I don't understand the lack of politeness. I can be driving along at say 10-15mph in a heavy queue on a main road, and I can see about 20 cars ahead of me not letting someone out or across. I always let people out, every single time.