I do wonder what would happen if:
a) Hertz did aircraft rental
and
b) Hertz did aircraft rental in the UK in the same way they did car rental in the US.
You'd have people throwing a hissy fit at the Hertz desk, turning down a complementary Spitfire Mk9 upgrade from the PA28 they'd booked because they couldn't fit the luggage in the Spit, and anyway it made their eyes water starting the engine when they were given a Spitfire because the Hertz outlet had run out of PA28s.
Of course, Hertz don't do aircraft rental because it is an entirely different risk proposition.
Hardly suprising then that if you walk in off the street, waving an easily-forged set of papers wishing to rent an easily-bent asset in the £50K-£250K range, that the people who to a large degree have their nads on the line are more than keen to ensure that the potential hirer isn't a muppet or a headcase.
The customer, eventually, is of course what keeps the business alive. However, this is a business where you have you distinguish between a customer, and an accident looking for a grid-reference.