Actually, they usually don't blame their own lawyer. With some exceptions, most people believe that their own lawyer was honest and treated them fairly. It's the other person's lawyer who was a lying, cheating, thieving son of a gun. That should tell you something.
Part of the antagonism toward lawyers is, quite frankly, based on partisanship. People see in the media a lawyer advocating a position with which they disagree, or representing a client who is guilty. They know the client is guilty because they have read all about it in the newspapers. These newspapers are written by reporters the public also doesn't trust, which creates a puzzling logical conundrum. In any event, to mix a metaphor, that's when the can of worms hits the fan. That's when people become mere pawns in a much larger ballgame. For some reason, the opposition forces are personified in the lawyer who is the advocate. People feel slightly better when they see another lawyer advocating a position with which they agree. "Now there's a lawyer you can trust," they say. "If only more lawyers were like her."
Still, negative reactions often tend to be stronger than positive ones, and many people are left with negative impressions about lawyers in general. They use a silent syllogism: since my position is eminently reasonable, the lawyer on the other side must be either dumb or dishonest, either a fool or a knave. The public generally perceives lawyers as being smart. Therefore, the only conclusion is that they must be corrupt.
But the lawyers know better, the reasoning goes. Because of their training and knowledge, we expect more of them. We do, and we should. But to blame one segment of society for all of society's ills is an old trick. If our society is too greedy, too dishonest, too litigious, too uncivil, then blaming one group or another is a cop out. We as a society should look in the mirror-- in good lighting-- and not angle our head just right, like we always do, so that our defects don't show.
Meanwhile, one economist asserts that each lawyer costs the nation one million dollars per year in lost gross national product. So I say, give me a cool $800,000, and I'll go home. We pay farmers not to grow crops, don't we?