Earlier quoted context omitted.
No, they aren't the same. Unfortunately, googling decriminalization vs legalization gets me articles that state the exact opposite of my understanding. As I understand it, decriminalization means making no law against it. Legalization means making laws about it that boil down to regulation. Thus, decriminalization is more free. This article seems to be generally in line with my understanding: http://time.com/3005687/…
The reason you get those google results is because your understanding is not consistent with how other people use the words. Your suggested usage is reasonable, but it's not the usage that is common, and I suggest that you change your understanding. Legalization has always meant "making it legal", which in most societies means "removing laws that make it illegal" (though it might mean something different in North Kor…
I don't think it's just me. It's a little more complicated than that.
I do try to be mindful that the words get used inconsistently and I do try to make a point of clarifying my intended meaning. I'm human and I don't always remember that this is an ongoing issue.