Some ideas, based on some of the ideas kicked around in this thread: What about something like compulsory licensing?

Copyright has something like this[1]. One can acquire a license to distribute a copyrighted song in some circumstances if you pay the mandatory fee.

So how would this work with patents? First, let's cover the non-practicing entity, or NPE. Patent trolls are the most well known and hated NPEs but they're not only ones. You can have a small time inventor who's successfully invented a thing, designed and built a prototype, but hit a wall when it comes to the capital-intensive requirements of moving on to actual production. As much as I might want to stick it to patent trolls, I don't want to catch original inventors in the blast radius. So it can't be something that just punishes all NPEs, but just the parasitic subsets.

So Bob discovers novel and efficient way to frobnicate foobars, and gets a patent on it. But he never takes it to production. Let's say materials science isn't quite at the point necessary that the materials needed for the frobnicating foobar can be readily had cost-effectively at scale. So he sits on it.

Some years later, after some improvements in materials science, it's now feasible to build frobnicating foobars at scale. And Bazcorp, a company that's in the foobar business learns of Bob's patent, gets a compulsory license to manufacture it, and starts building and selling frobnicating foobars. Bob gets money for the frobnicating foobars now on the market, Bazcorp gets to sell frobnicating foobars, and people get to buy frobnicating foobars. Sounds win-win to me.

Now, how keep patent trolls from perverting this? Make it so the fee schedule for a compulsory license is lower if the entity holding the patent gets more than, say...10% of their annual revenue from license fees. Make it so the liscencing fee schedule goes lower the older the patent is. You could combine this with annual fees to renew the patent, escalating each renewal period that the invention in the patent is not being produced, making it more and more expensive to hold a patent on a thing and not be building the invention covered. Then add a multiplier upon the renewal schedule if the patent holder gets more than 10% of their revenue on patent licensing.

So Troll, Goblin & Associates, LLP, seeing the hot market for frobnicating foobars, does some research and discovers building them is covered by a patent they hold on the quux process. Said patent is 10 years old now, and has cost some coin to hold on to, so it will require quite a lot of money to turn a profit on it. So, TG&A goes to Bazcorp and demands one million dollars per unit. Bazcorp calls TG&A's bluff and files for the compulsory license of $0.10 per unit. Now, with the volume of frobnicating foobars that Bazcorp is moving, TG&A still gets a not-insignificant sum of money, but not enough to break even on the purchase of the patent and fees to renew it. Too bad, so sad, such is the risk of TG&A's non-creating, parasitic business model.

Another idea: What about something like jury duty as assistant patent examiners? The patent office could reach out and compel persons skilled in the relevant sciences to assist with patent review and be remunerated for said assistance. Then, you might actually get some qualified eyes upon patent applications that could spot prior art or obvious things and reject said bogus applications.

1. https://www.copyright.gov/circs/circ73.pdf