I think so, less skilled and faster = cheaper to install. They couldn't care less what happens in 10+ years time.
BTW pushfit and plastic don't have to go together. I have occasionally used plastic with compression fittings, and that works well. A case I can think of was routing some pipes through an airing cupboard past the hot water cyclinder, which was only expected to be there a couple of years before being ripped out (and it's being ripped out tomorrow).
Beacause push-fit is seen as a low-skill operation, it's often done by people with no skills at all, and you see pipes pulling on fittings at the wrong angles, fittings supporting the pipes, and all sorts of other horrors which shorten the life even more.