Now I understand the extenuating circumstances: a registration process that's been reported to have a half-hour wait even for pre-registered attendees when there were only a few people in line. Makes it real difficult to register. Still, that's a hurdle, not an excuse.
Yes, I know, even if you had paid your membership, it wouldn't have made a difference in the convention's failure. When a convention features that high a concentration of weapons-grade bolonium it's going to fail with or without you. That's kind of the point, though. If low registration numbers are a problem for the convention, being there without registering makes you part of the problem. Don't go. Go wine-tasting instead. Throw a party. Do something fun. Spend your time contributing to some other event's success. Don't make yourself a part of the failure.
Yes, I know, badge Nazis suck. Guess what? You just helped them justify their own existence. Most con security folks aren't into making trouble for attendees, but some are. If you don't give them the opportunity, they don't get to have their fun. Enough of that, and if we're lucky they get bored and go find some other event to volunteer at where they can get their authority fix. Think of it as antisocial Darwinism.
Finally, think of the volunteers. A lot of people have spent a year working to ensure that a con is a success (OK, in the case of con-X-treme I'm guessing two people, a wedge of cheese and about three weeks based on the results), and they're going to feel crappy enough if nobody is there. After the ghosts whining about badge Nazis at Anime Los Angeles, I pretty much summed it up as "I didn't spend the last few months preparing things, answering questions, taking vacation time, getting my own hotel room and driving 300 miles down to Los Angeles for a bunch of fucking freeloaders to bitch about not getting the fun that they didn't even pay for." Are you a fucking freeloader, or are you a participant in a community event?
Seriously, if you think an event is going to suck and doesn't deserve your money, don't go. If you're not planning to register, don't go. There's got to be something better to put your time into.