Hip hop hypocrite

Why is it when someone gets caught doing something, they simply say they are going to rehab and think that is an answer?

That freshman congressman - the hip hop congressman - so he calls himself.  He also voted to force people getting food stamps to take drug tests. 

Got caught in a sting and bought coke from an under cover cop. 

He is reporting he has a problem and going rehab?  He is going to take a leave of absence and donating his salary to charity?

Why is that the answer?  The answer is you like to drink and do drugs and you are a fucking hypocrite. 

Is there rehab for being an asshole?