On the contrary, when people complain it shows they see it as essential. They don't complain about non-essential online services; they just stop using them. I get excited whenever an OurDoings user sends me an email full of complaints.
But she's not complaining to FB, she's complaining to me and probably her friends. Word of mouth got FB started, and word of mouth will probably be it's death.
I complain every time there's traffic on the road I use to get to work. It doesn't mean I consider it essential that I make it to work in 6 minutes instead of 11. People complain about all kinds of inessential inconveniences.
When I say "service" I'm talking about the road. Getting to work is worth the inconvenience. That you complain instead of not driving on that road shows how much you value the road.