The only good reasons I can think of are: * To ensure the other person isn't in a meeting. The sender might not want the text to be broadcast unintentionally.

The only good reasons I can think of are: * To ensure the other person isn't in a meeting. The sender might not want the text to be broadcast unintentionally. * To force a synchronous conversation. I think this is pretty rude though. What would be better would be some context and an aim to get a time that suits both people. Something like: "Hi Mark, do you have any time today to get together to discuss the ongoing database issues? I have two potential ideas for the cause."