Brand new 6-drum winches are expensive but so are six brand new air conditioned towplanes with entertainment systems and disabled access.

Almost anyone can be trained to drive a winch. I've launched loads of gliders using a homebuilt single drum winch. Also run the start line, driven the buggy and taken quite a few launches including ones that started XC flights.
In a crosswind, it's the glider pilot's responsibility to stay upwind of the runway so the parachute falls on the runway.
A winch operation can be run efficiently with two people. The person who hooks up the glider and runs the wing can drive the retrieve vehicle.
Auto tows are fun too, but they are nowhere near the fun of a winch launch.

Had held on this for fear of the off-season rants on this particular glider.
On Saturday I witnessed another reason that ground launches are not common in the USA: The most common US trainer is pretty poor at ground launches.

Jim