I hear what you're saying but I've seen many boater give up and go home when their computer transmitter just won't behave so none of their boats can be used. My solution is quick to fault-find - just plug & play. And percentage settings seem to be over-the-top - sticks don't have to hit the end stops.
A fair point, although I've not witnessed that, as I don't think many at my club use computer radios to do anything "fancy", apart from one or two who also fly planes.
I've only ever used Futaba kit for planes or boats, and it has always worked perfectly.
I guess it depends on what one is used to and comfortable with
What I meant by "percentage settings" was the amount of positive or negative throttle added by using the rudder. A large amount of "outside motor" can be very useful at low speed, but might be disastrous at high speed.