I agree that there are some lazy TM▸ 's but lately I've also seen a fair share of lazy conductors!
From my recent experience it's relatively unusual to get checked on a unit between Bath Spa and Bristol TM, even on services which call at Keynsham and Oldfield Park (both unstaffed for most of the time). Even when the train is on time and not unduly crowded a few conductors never seem to emerge from the rear cab.
From my frequent journeys to and from west Wales it seems that ticket checks on
HSTs▸ between Reading/Didcot and Swansea are the exception rather than the rule, even occasionally when there's more than one TM on board!
Of course, it goes without saying that although there are some lazy conductors and TMs (as I guess you would find in any job) there are plenty of extremely hardworking, helpful, conscientious and enthusiastic staff as well!