Patent trolling is usually the last gasp of a failing business. Which implies that despite (or because of) their overpriced hardware they are failing as a manufacturer; GPus are now commodity items and the margins no longer exist to run their type of high-margin business.
Patents are a cruel abomination which distort the workings of a "free market"; they directly codify rentier behaviour which costs society both economical and technological progress. The only beneficiaries are the unproductive leeches of society at the cost of everyone else.
If you're an engineer or scientist who is currently using or considering cuda for your work I suggest you reconsider both to protest this failure of a strategy and to protect the future value of your work.
Just for nvidia to consider this strategy shows they are not long for this world and choosing to use such a single-supplier would be foolhardy.