You're not forced to use Windows either. There are plenty of alternatives to that. Even then, I use HeroLab on my laptop running Linux via WINE.
If the company disappeared off the face of the Earth, naturally there could be serious problems though if we're lucky they wouldn't try to screw their fans in that scenario. (I actually have more faith in smaller companies over that sort of thing than I do the "big guys.")
Per node licensing is really the norm these days. Not typically seriously enforced though it is more and more. Though considering you get a "free" secondary license right off the bat for another machine you own.. I really see them as being kind personally.
Never had any trouble with activation myself.
I do understand the concerns with swapping out computers or OS reinstalls. Though you get to swap the license to a new machine no questions asked every six months I believe. If you're swapping out computers faster than that or needing to reinstall your OS more often than that, well, you have other issues to worry about if you ask me.
That being said, you're perfectly free to make your own mind up. There are plenty of alternatives to Hero Lab. I happen to use it because I find it to be the best for me. I accept that piracy prevention methods are something to live with in the face of.. pirates. Activation like this is one of the best countermeasures I'm aware of really.