Honestly I don't mind this si much because it means the rest of the opening is coming along soon. The real issue is when someone slacks me "hi" or "you there?" and I am doing something or in a meeting, then see it 30 minutes later and reply but they're not around to tell me what they wanted.
This is in English but it should really be in Turkish, Hindi, etc because there are cultures that do this 9/10 times, and cultures that do this 2/10 times.
Sure it's generational too.
But in some cultures it's not generational- people can't merely write a question without waiting for your "Hello" response, and then your "How are you, I'm fine thank you, and you?" response.