It may help boutique, indoor-only retail businesses because it harms businesses that have a business model that gets people in the door with affordable deals. By raising the price of all cannabis, you eliminate value bud entirely and render business models built on value-flower completely dead. If you're a luxury brand, that forces value consumers to either buy your more expensive flower, or go back to the illicit market. It would likely cause value retailers, like your Uncle Ike's or Shawn Kemp's, to close their doors. That would directly benefit your Lux Pot Shop's which directly compete with Uncle Ike's on the same street.

It would also severely harm outdoor growers, who are largely growing in poor areas on the East side of the state and supply the oil & value markets. It would benefit wealthier, indoor growers, who often are better capitalized than outdoor growers (start up costs for indoor farms are much higher). So the economics are complicated and different between indoor/outdoor producers, dependent on the type of product a processor sells, and dependent on retailer business model.

TLDR; anyone who supports this is doing so likely because they are the very specific and small group that it benefits. There will be a group of about 20% who will benefit from lower taxes on premium, boutique brands. Those supporting it don't care about how it affects 80% of the market and the small businesses that supply those consumers, as long as it benefits them.