we who repair mowers and in my case tries to get 100 year old motorcycles know just how hard it is to tune an engine so it simply runs, let alone runs between a very fine pair of emission limits.
When it comes to mowers, they are required to run at a set ( Governed ) speed.
There is no reason to ever run them slower than this speed.
The shape of the blades, the shape of the deck and the speed of the blades are all matched to work together efficiently.
Add to that product liability means that mower companies get sued if you open the discharge chute with the engine running at full speed and a rock or stick flies out & hits you.
So the domestic models for the idiot stupid brain dead average mug pushing a mower over their grass with their mind 1,000,000 miles away have 2 speeds, full & off.
Thus to remove the catcher you have to turn the mower off.
Professionals have their mind on the job.
They watch what they are doing and understand fully what is going on.
They also empty the catcher 20 times a day.
They will recognise a patch of sandy soil that needs to be mowed at a slower speed .
Add to that, professionals are covered by workers compensation insurance and are less likely to do something bone stupid, injur themselves then sue the mowr company because their own stupidity has caused them a financial loss.
So there are two types of villians that cause this to happen
1) Beauricrats making legislations for the purpose of pretending to be doing their job ( Most EPA )
2) Lawers getting massive payments for people who in reaity should be admonished for their own stupidity & be compensating every one else for their cost to the community.