Re: They can't be a true patent troll until they quit making products
I don't agree with that definition. I think a company that formerly made stuff that is now just a shell that owns patents and sues people is as much of a troll as a company that buys patents and sues people.
What you're talking about with constantly modifying patents to resemble existing products is something else altogether, but it is no longer a problem because 1) submarine patents were banned and 2) there's a paper trail for the modifications submitted to the patent office so since the US is now "first to file" rather than "first to invent" if they don't get the paperwork with the changes in BEFORE the "something that someone else is making" becomes publicly known, they won't get very far with the lawsuit.
Your scenario was only a problem under a "first to invent" system where they could claim (whether true or not, engineer's logs can be faked) that they had actually invented it before the company coming out with an actual product did. Fortunately that was fixed with the patent "reform" a few years ago.