[count-your-change]

For an answer you might have to ask a grower but some things are just too obvious. I suppose with actual legalization would come quotas and taxes and various regulations and record keeping.

Growing in a national forest avoids all those problems for the grower that doesn't want the oversight that might cut into profits.
Legalization might work like tobacco growing. Heavily regulated and taxed and only the larger companies able to market the end product.
But would legalization stop imports from cheaper growers?

[Pearls Before Swine]

I suppose with actual legalization would come quotas and taxes and various regulations and record keeping.
Growing in a national forest avoids all those problems for the grower that doesn't want the oversight that might cut into profits.
Legalization might work like tobacco growing.

If you are talking about legalization like alcohol or tobacco, you are talking about partial legalization. Then, what you say about tax, oversight, and possibly the black market could be true, depending on how onerous the government regulations and taxes were.

On the other hand, you can brew your own beer and make adequate amounts of wine for your own consumption without tax or interference. I don't know if anyone cares if you grow and cure your own tobacco without resale, or if the personal product is palatable.

With pot, growing enough for satisfactory personal consumption is said to be easy; and the quality is probably good enough, unlike the homebrew beer I used to make. That would make many of the regulation problems you describe less onerous, and would make the appeal of black market growing drop markedly.