One of the problems here is, even if you have a rental car reservation, they might not have anything to give you when you show up. Or, you reserved a van, but all they have is a Ford Fiesta.
One of the arguments in the article mentions overtourism. They seem to believe you can reduce the number of tourists visiting at any given time by keeping car rental prices high. I think if the rental prices keep people from coming, we're hurting our main source of economic revenue for hotels, attractions, restaurants, airlines, and so on.
The real problem is the number of cars on the roads in general. Singling out rental cars and limiting their numbers by making the tourists pay more seems ridiculous. Do we want them all to take that money and pay for a tour bus? Those make traffic even worse. Maybe we can just hand out complimentary passes for The Bus for to everyone who arrives without a rental car reservation?
People always know why we shouldn't do something, but they never have a good alternative. Trying to get around on these island without your own car can be impossible if you want to go to luaus, shows, sightseeing, etc.
Then again, fewer rental cars means fewer break-ins and thefts. Might have a point there.