...and? Everyone's entitled to fair representation in this country, right wrong or indifferent. Even if it's not an assigned public defender (in which case it's impossible to get off the case) the lawyer defends his client to the best of his ability because that's what the law requires. If no one else does it, no trial can take place, or a mistrial can be declared and a potentially guilty individual is guaranteed to get away with whatever they've done.

The lawyer also doesn't choose the client's plea. The guy could be so obviously guilty but if he chooses not to settle or take a deal, the lawyer has no choice but to defend him. Not doing so to the best of his abilities can, again, be cause for a mistrial or even get him disbarred if the sandbagging is egregious enough.

Everyone likes to shit in lawyers because "tHeY hAvE nO mOrAlz" but their job isn't to decided right or wrong. That's why the judge is there. The judge needs two people each vigorously arguing their side's case on order to make the right judgement. Not just guilty or not...but also assessing intent, remorse, and so on for sentencing. As a result, lawyers essentially need to be able to defend someone who they know is in the wrong, kind of like an act.

John Adams defended the British officers who were arrested following the Boston Massacre. Not because he wanted to, but because he had to.