Your 135,000lb grey beast is operated in a completely different environment to the environment we operate in. Not saying someone who has done well in your environment wouldn't do well in ours, or vice versa. But the training to get to the same end stage is very different, the supervision along the way is very different and the outcome from failing a flight is very different.
No doubt along the path to flying a 135,000lb grey beast you've gone some extremely stressful points in your life to prove you deserve to be there. In our environment this is one of them.
Because of the inconsistency in our training, the regulator occasionally steps in. With pay for your own endorsements, training budgets have been slashed, there often isn't time to repeat a flight. With pressure from management to get a certain number of pilots on line, some candidates are passed when they possibly shouldn't be.
At this point the regulator has two options... they could put their foot down with the airline(s) and say their type conversion was inadequate. But this is a big political game and one they don't want to get involved in. Or they could simply make the standard to get to the interview stage just that little bit harder and tweak an exam that they do have control over. The only people who are going to complain aren't in a situation to do a lot about it. Guess what they decided to do?
This happens every few years, they watch the outcome and silently tweak in the direction required. Some times things get harder, sometimes an extra half hour is allowed in the exam, some times a few questions disappear.
Would this be better done at the airline level with a company that has the resources to retrain as required if someone doesn't meet the standard and the material can be made relevant to the type in question? Absolutely. But the industry is moving as far away from that as possible in an attempt to cut costs, and hence the ATPL is being used and expected to check knowledge to the level required for the first type rating, albeit on a semi-imaginary aircraft (B727 Flight Planning, combination of 767 and 737 systems, etc.). If someone isn't meeting the grade, they simply have to pay to retrain until they do. Then when they come to do the second type rating (the first real one!) there can be an assumed level of knowledge and the airlines can pay the bare minimum in training costs.