Texting is simply another way to make a phone call. If you as an sp would not call up a client out of the blue, looking for biz or just to chat, with a phone conversation, then doing it by text is not any more OK.
An email can be opened in private, and not be viewed by anyone but the recipient, but a text just shows up. You have no idea where he is, who is he with, what he is doing, and there is simply no good excuse, whether you wish to know how he is or not.
It always comes down to one thing, when it comes to clients making appts: when they are ready (time, funds, interested), then they will contact you. Calling them up out of the blue will not make them any more available.
I only have two people I talk to with email, I would never call anyone up except to return a message. I feel mostly the same way about the emails. I will wait for contact, then reply as quickly as possible. I just feel nothing good comes out of calling people up.