Passwords?

I suppose it's because I'm a new blogger - and next to no one even knows I exist - that I don't understand, but what's with the recent proliferation of password protected blogs? This is a serious question, not a rant. Used to be you could wander around cyberspace clicking on blogrolling links and "meeting" interesting new people. No more. A lot of blogs I used to lurk in are password protected now - upwards of 25% anyway (maybe closer to 50%). These are people who had interesting, thought provoking entries but who are now lost to me.

So tell me - why password? Is it something you're considering for your own blog? Enquiring minds want to know.