I agree with the frustration. I seldom play the freerolls there anymore because it just is not worth the time and effort. Too many people, too little gain. Then, again, I have a sufficient BR to play the games that I like.
And, oddly enough, despite swings, despite the regular beatdowns, my BR remains relatively intact. BRM, combined with self-policing tilty times, has worked wonders. Also, trying very hard not to do anything stupid has seriously helped my game. When I do experience a serious downswing, my first thought is that it's me. I have yet to find a point where my game was leak-free and it was all about variance. There's always been something I am doing overall that is hurting my longterm results. Always.
BRM doesn't work if one's play is not good enough, although it can extend the time you can play on what you have. If one loses consistently, it's not the site. And even the big winners, the best players, lose a ton of hands, sessions, tourneys -- but they make up for the losses elsewhere, at other times. And this is, in part, because they can fix their game, improve, and not sweat the times there is a bad result to a good play.