It seems to me that his arguments about decriminalization apply equally well to cannabis. If nobody can be arrested for cultivating or possessing pot, then why legalize it and turn it into the huge industry it is becoming?

As best I can tell, decriminalization means not enforcing the law. That is a very bad idea. Laws should be enforced, and bad laws should be fixed or eliminated.

If the author means that personal use and cultivation should be legal, while commercial operations illegal, why not describe it that way.