Like every profession, there are good and bad lawyers. I happen to know a lot of good ones -- honest people who work hard for their clients, sometimes pro bono. Take Dave, for instance: a public defender who could be making a LOT more in private practice, he is decompressing after losing a high-profile murder trial (the girl was stabbed 27 times by two of her high school classmates). He put in, quite literally, hundreds of hours -- but it's kinda hard to defend when your client and his friend videotaped themselves planning the murder, videotaped the body and your client standing over it, and commented on it afterwards on the tape -- all on the same tape.
I could cite others, in and out of criminal practice. And I could cite those who traded services for sex, sold cocaine from their offices, slept through trials, and attempted to bribe juries and judges.
A lawyer seems "crooked" when a) the client is charged more than the client thinks proper and/or in spite of the best efforts of the lawyer the client loses (sometimes because the client doesn't tell their lawyer everything).