Well, it's not prohibited by the rules, is it?

People are different – in their perception, composure, pickiness, and their possible online availability. Some people, after waiting 2-3 minutes for you to make your move, start freaking out, claiming you're a jerk who respects neither them nor anyone else, regardless of the situation. Thankfully, these situations can be resolved within the community by choosing opponents with whom you can communicate normally and who will understand if you need to step away to soothe a crying baby, etc.
It's a shame there aren't tournaments with divisions based on the availability to play during certain hours (e.g., 6 PM - 11 PM; 8 PM - 12 AM; 10 PM - 2 AM). Of course, there's always a grain of truth in every joke.