That could be the an explanation for only having high potency weed in areas where it's prohibited, but it's equally available here in Canada where it's legal. I think people just like it.
I'm saying that high potency products are still sold in legalized areas as there's demand for it.
I remember having issues years ago finding low but not non-zero THC products on the government website. I had to get 17% which is still high. Things may be different now.