I'm both happy and unhappy at these checks, but have only personally been 'checked' the very rare time over the years because I try not to take the P and travel considerately. Yes, way too many do seem to misunderstand what is a reasonable amount to bring as cabin baggage, but also it seems that there is a incentivised revenue stream at play as well, which seems to rule out reasonableness especially with soft bags that are by nature a bit lumpy and might not fit neatly in the bag measuring cages at the gate. Perhaps a standardised size of cabin bag allowance (depending on aircraft group size) across the industry might also help with cabin baggage misunderstandings ?
As mentioned above, it is the inconsistency from the airlines and staff/contractors that seem to be in dire need of an overhaul, so that passengers can see that they WILL be penalised if they disregard the cabin-baggage rules, but that the rules and attitude are fair and seen to be fair. I would also like to throw in the ring that there should be no special grace given to anyone based on gender, a seat occupying passenger is simply that. Passengers with young children and passenger carrying medical devices as before unaffected.