I don't think all PAYE jobs are like that, just most of them.
Its the firms who look after council and HA contracts that are the scumbags.
Its a numbers game with these firms as most of them don't get paid until the CP12 is done so don't care how good the service is or how many a bloke does in a day as long as its double figures, which is terrible :-(
i know a bloke who works direct for a small local building firm and all he does is boiler swaps and service etc, he has no pressure to do loads and he is the happiest gas man I've ever met