How much does an engineer cost to set up this Computer based system and keep it updated and running smooth. (Not everyone wants to be stuck in front of a computer screen, most just want to get home, switch on and play)
Another point to remember is how many partners would allow multiple keyboards, wires etc in the lounge. (This is where most instruments go; and they become part of the furniture)
So while you are correct about it is cheaper to use a computer, (Providing you forget about the engineer costs) in reality in most cases it is a No Go proposition.

Bill