It doesn't make any difference to them if they allow or reject patents. The more rounds of prosecution it takes means more counts for the examiner. Each round after the first requires additional fees from the applicant.
If it were differently administered would you be fine with it?
If the UKIPO is granting invalid patents the checks are that anyone can petition the comptroller to check the validity of a patent, anyone can submit prior art for the examiner's consideration. Then, a patent that's invalid should be useless in court and just accrue the holder their own, and the defendants costs.
In practice companies go for invalid patents because they can lawyer their way out, but that's the court system that's broken then.
TBH that doesn't sound like an awful bad idea.
The US government already does something similar for corn. Farmers are paid to not plant it to control market price.
(1) Informal norms among the fishermen as to how much fishing you should do. This system is not resilient to immigrants, who don't know the local norms (and may, not unreasonably, feel that the local norms already allot all of the fish to established fishermen), so fishing communities are often fiercely resistant to newcomers.
(2) Legal limits on how much fish you can catch. The idea is that an authority will determine the total quantity of fish to be harvested, and then allot rights to harvest smaller quantities than that piecemeal. Under this system, taking fish without an appropriate license is a crime.
You could move to a system more like our agricultural subsidies (paying people for the pigs they didn't raise), by giving money to anyone who owns a fishing trawler but didn't bring in any fish. But that seems obviously insane compared to the permitting system.
"Informal" cultural norms operate as laws on a small scale, maybe a pre-industrial community and a lake (or grazing commons, like various feudal Europe examples). Any scale that implies depleting oceanic fish is a way to big for this. I would be surprised if any modern era conventions applied to ocean fishing for migrants to have any influence at all.
Cultural norms generally operate on a small group of people. In the modern day, it doesn't take very many people to catch a ridiculous number of fish. So depleting ocean fish is better handled by cultural norms now than it was 500 years ago, when catching a lot of fish meant fielding a lot of boats.
That greatly depends on the type of fish and is not generally true. Many species of fish spend different parts of their lives at different locations. Tuna, salmon and many other pelagic fish travel pretty big distances.
Of course there are complexities to both the approvals and rejections (office actions), which have to be justified and potential reviews by other examiners. So it may be broken, but not the way you imply.
They encourage patent owners to abandon patents earlier than their maximum term (20 years after filing) if they don't want them any more.
2- Isn’t having to pay troll deterrent?
3- How would you fix it?
Assuming you're right, how would you fix the incentives?