The problem with these stories is there is a lack of context. If the person read the message at 8PM do you think they should still answer or wait till tomorrow during normal business hours? Personally, business can wait. Unless its an emergency, I don't feel I need to answer just because I saw the message. If I am answering after hours (which I believe even freelancing has after hours), then that is a premium fee.

My approach to business is to write emails. I don't believe its professional to text a business associate unless there is an emergency and then that should prob be a phone call. It looks like many other responses said the same thing. Just my two cents after two plus decades working in offices and management.