I keep hearing "legalize drugs" and the drug dealers will cease to exist.

They are criminals that are currently engaged in selling illegal drugs because it is very profitable.

If they cannot make large amounts of money dealing drugs they will find some other criminal activity to enrich themselves with like theft, kidnapping etc.

Then what? Legalize burglary? Legalize kidnapping?

Criminal activity must be dealt with by the law, not by the false logic of legalizing crime.