First off only stupid pot growers steal electricity.
Secondly, growing pot is far far more work than running a bitcoin farm.
You have to start seeds, or maintain mothers. You have to clone - prepare plants for flower. This alone with roots and good growth can take 3 weeks to a month. Plants need watered constantly. Even a very automated hydroponic system needs water and nutrients topped off every other day. There is always work to be done. I'd say a 4000w system to keep running no with interuptions between crops you are looking at 2 hours a day of work. Then once the harvest comes in, I'd say at least very minumum 24 hours of trimming work. A week of drying then more work preparing for sale. Not to mention the complete cleaning of the grow space between crops, more hours of work.
Heat from a garden is way more than a mining rig will ever think of being. Then you have to dispose of the heat. Try dealing with 4000w in the middle of summer
A professional gardener will make so much more with cannabis than with a bitcoin farm. A professional grower will be doing 1.5lbs per 1000w and most pros will have 3000-4000w minimum. So 4-6lbs every 60 days. Retail in my area for high end dank $400/oz x 64oz (4lbs) = $25,000 every 60 days on the low end.
Gardening is a labor of love and for a professional it is a very lucrative endeavor. I'd still be at it if it wasn't for a few douchebags with badges.