You're absolutely right. I do know people who use cracked versions of software they legitimately bought, just to get rid of the f*cking iLok.
I'm not a fan of copy protection at all. From an engineering perspective, it's a single point of failure and its sole function is to render the software unusable unless some intentionally-obtuse set of criteria are met. At best it provides zero functionality for the user, and at worst (its only other possible mode of operation) will give a paying customer headaches.
I can completely sympathize with someone using a crack for reliability.
But those users can always fall back to the legit version in a pinch, can always call the vendor for support, and are always up-to-date with revisions. They're not risking much, and by my reckoning aren't even pirates.
But how often do plugins actually fail, and what's the worst that could happen if one did? Fortunately, they don't fail often, but when they do it could be major. Take Waves stuff, for example. One Waves plugin won't fail - they ALL will.