There is no way legal marijuana will ever be a financial boom to anyone in the business legitimately.
UNLESS. Unless they want to deal with ILLEGAL marijuana as harshly as possible.
Illegal alcohol was dealt with harshly. Illegal tobacco was dealt with harshly. Both were dealt with until it became unwise or unprofitable to do manufacture it illegally.
If people can buy illegal marijuana with no recriminations then why in the world would they buy legal marijuana that MUST cost much much more?
Excellent point. Let's take Massachusetts: For years they had medicinal pot and you can purchase an ounce for around $300+. So many buy this weed and resell it to their friends and neighbors. So along comes legal weed and they want $400+ an ounce. Guess what? People went back to buying the "medicinal" weed cheaper. When governments get greedy...
Quality control.
In my state, legal retail sales are highly regulated. The product must come from a licensed and regulated grower. It is tested by the state and must bear a label stating the potency and % of THC, CBD etc.
You pay more so you know what you are getting. Just like buying anything else - you can take your chances on the black market or you can pay a little more in a regulated retail facility and have some assurance you are getting what you paid for. Some people prefer that, even though there is no penalty for having an oz of bootleg weed in your pocket.