Paradoxically, trusting strangers has also made my life safer.
In Armenia, I met an old woman who then helped me get through a dangerous area and told me not to worry - she'd protect me like her own grandson :) In another country, I made friends with an army officer who watched over me, and somewhere else a truck driver helped me through a tough border crossing.
People also seem to be scared of that one crazy person who'll stab or rob them. Here's one thing I realized: even the "bad" members of society are not bad to everyone. A mugger doesn't mug his friends and many murderers have been loving parents. Getting to know someone - aside from being interesting - means they'll see you as another human being, not some target. (Most of the time. Of course, always use your judgment, and if something feels off, just leave.)
I hope CS gets reborn. Who knows, it might happen - maybe they'll run out of cash, put the site up for sale, and someone will rebuild it as it should be. Or maybe the current leadership will do a 180 (unlikely, but who knows!)
I'm sad that all those good memories will be tinged with pain by this betrayal, but it's given me a good reason to get back in touch with old friends, and invite them to BW. I wholeheartedly agree with your descriptions of CS and trusting strangers; you've had some great stories!
More than anything, Couchsurfing taught me wonderful things can happen when you embrace serendipity. Couchsurfing is an important antidote to a world that seems increasingly fearful of strangers.
I hope they manage to survive.