Patent trolls (the most successful ones, anyhow) practice Batsian Mimicry as a defensive strategy: they specifically try to look as much like a small inventor who's invention has been stolen by one or more bad actors. It is never simple to disrupt an evolutionary arms race.
> I imagine a simple addition to patent laws invalidating a patent if the holder does not commercialize it after a certain period should get rid of NPEs. Is it not that simple?
Are you aware of how long it takes drugs, for example, to get from the patent stage to the commercialization stage? I'm sure there are other obvious industries where this would be problematic to the normal way of doing business.
On a more broad note: is it good to require that all inventors directly commercialize their own inventions? At best, I think this is an open question.
The public good is a priority. The idea is that the invention is beneficial to the public. If somebody creates a good invention but deny it from the public, this patent should not be in public interest anymore.
for about 15 years.. After 15 years the public can make use of the invention without paying a penny. How it is not in publics interest?
Patent law already handles this providing pharma patents additional protection time for regulatory delays.