This is a bit different from the last stamp about being relevant.
Making sense is important too. And I don't mean language barriers. Some people I've seen talk about their dog, their brother and some problem they have, then make some conclusion about a picture in one sentence which isn't even that
coherent. WHAT the FUCK are you talking about?
If you speak English, and it's your first language make some SENSE! It's not that hard.
Oh, and don't forget about the kiddos who think they're being 'unique', random', 'cute' or 'funny' when they make little sense when commenting. Hate to break it to you, but it's not any of that. It makes it so fucking hard for us understand what is being said that it just makes conversations with the other person a non-enjoyable experience.