Mainly because the businesses don't really want to talk to you. Talking to you means that they have to deal with your request, complaint, etc. right now, instead at their chosen speed. Also, dealing via internet means a record of what you said exists, as opposed to what you said you said (don't fall for the "this call may be recorded for quality assurance.....those records are seldom available).
I know what you mean, though. Sometimes I want to talk to a real person, instead of trying to make my request or question fit into a computer category. That's when you get, unfortunately, "Your call is very important to us; please hold (and hold and hold and hold......) for the next available agent."
I'm afraid it is what it is....."people" are on the way out and "HAL" is definitely taking over.