Did you get past the first paragraph?
The phrase that I saw used in the actual article itself, rather than the leader, was "patent-assertion entities" which is to say companies whose primary line of business is suing for patent rights.
That said, some of them are suing on behalf of entities like your law school alma mater. But the entities doing the suing have no other business.
What does it matter whether the entities doing the suing have no other business? Say I buy a really popular strip of land near the beach and don't do anything with it. Say that attracts a lot of tourists who picnic on it illegaly. Is it illegitimate for me to sue them for trespass? Say I sell off the right to sue for trespass to a non-practicing entity. Is that illegitimate?
Now, you may disagree with the nature and scope of the rights. You might say--people shouldn't be able to buy land by the beach--that belongs to the public (and that is the law in some places). But once you have a valid property right, it's not illegitimate to sue for real infringements of that property right, and it's not illegitimate to split up the "bundle of sticks" that makes up your property right and sell someone nothing more than the right to sue for infringements and keep any damages. That's just how property rights work in general.
In your example, you want something you didn't buy: access to a public road. I have three ways to monetize my property right with respect to you. I can sell you an easement across my land, I can lease you an easement across my land, or I can sue you for trespass and collect a nominal damages everytime you pass my land. The latter is somewhat inefficient, but all are totally legitimate--they are all just ways to transact in property rights between the two of us.
Using terms of "victim" and "vulnerable" are really inapropos here. A lawsuit is not an "attack." It's a "hey, I think you owe me some money." These are businesses all trying to make profit off inventions. If the patents in question are valid and legitimate (and I think a lot of them might not be, to be fair!) then there is no illegitimacy in a non-practicing entity suing to enforce their patent rights, because ultimately those rights derive from the original inventor. The NPE might not "create anything of value," but the inventor did, and the NPE bought out the inventor.
Now, to be fair, lawsuits are in inefficient way to transact in property rights, even if they are a legitimate way. Most people who believe in the patent regime think we need to develop things like patent markets to make it easier for companies to find and license patents without resorting to lawsuits.
Now, you may think that intellectual inventions shouldn't be the subject of property rights. That's an entirely defensible position, but it's also a totally separate issue.
You acknowledge this, sort of, but only when using the loaded language intellectual inventions to describe patents. This deliberately ignores the fact that a major complaint about the current patent system is the proliferation of patents which claim "invention" status to things that should not be called inventions.
You then go on to call the question of whether patents should be property a totally separate issue. I agree that it is totally separate from the line of argument that you want to pursue. But, given the opinions of most people on this site, it is actually the central issue. Your sophistry about property laws is actually the side issue that should be ignored in favor of what is really important.
The key question is this, is the rapid proliferation of lawsuits from non-practicing entities a problem? In fact evidence suggests that the companies being sued are generally ones that are creating real innovation, economic development, and jobs. The companies doing most of the suing are creating a tax on innovation. If you look at who is paying the costs, and who is capturing the profits, by and large the patent system is failing to incentivize actual innovation, and is rewarding useless legal activity.
When you look at it in this light, the activity of the non-practicing entities is absolutely the greatest source of the gap between what the patent system theoretically should be doing, and what it actually is doing. Therefore the rapid proliferation of lawsuits by non-practicing entities is direct evidence that our bad patent system is rapidly becoming worse.
Now, like a good lawyer, I expect you to take apart and criticize everything that I've said. After all you're paid to come to the conclusion you've decided in advance to, rather than to find the correct answer. Truth, for a lawyer in an argument, is merely one source of rhetorical ammunition. I admit it. I am not a lawyer. In a war of words, you'll win.
But I honestly believe that the ideas that I am putting forth are correct. And the ideas that you are putting forth are dangerous ideas that currently cost our economy tens of billions per year. Furthermore those costs are rapidly mounting. For decades now, Silicon Valley has been the world capital for tech startups. Some day, hopefully a long time from now, this will end and Silicon Valley will pass into history. But it could end much sooner, and worsening patent laws are on the short list of things that could end it quickly.
Also, I should note that I'm not a patent lawyer. I'm not paid to come to any conclusions on this issue. I have a somewhat more pro-patent outlook than many on HN, but I think it's one that reflects the prevailing view among engineers who have more traditional backgrounds (mine is in defense/wireless communications).
As for patents and engineers, I think it is likely that opinions differ. And one of the causes of that difference is that in software it is easy for random non-technical types to create broad patents with little merit by slapping "web" on top of obvious generic ideas. By contrast in hardware, patents are more likely to come from actual devices created by actual engineers, and therefore you tend to have fewer of the truly egregious patent abuses that outrage people on the software side.
By analogy, what does it matter that mobsters are able to demand "protection" money from legitimate businesses? If it was their right to threaten and demand payment without doing anything useful?
I'll tell you why it matters: because demanding payment from society without contributing back in any way is deplorable, criminal behavior.
It's more like if someone buy's out your landlords interest in the building your apartment is in and sues you on your lease. That's not a protection racket--that's enforcing your legitimate property rights.