This makes sense to me. While cannabis is well-known in Russia, attitudes towards it are mostly disparaging where not hostile even in relatively enlightened Moscow. The druggies there tend to be more hardcore anyway. It is a large part of the conversation in the UK – see the debates over what classification it should get – but actually getting hold of it wasn’t easy (I never managed to at any rate, though in fairness I didn’t try; nor did I ever see a weed circle).
In contrast, weed is ubiquitous in the US – well, at least in California. There are books on cannabis horticulture openly sold on the streets (some go on to put this knowledge into practice in secluded inland forest glades). There is the 4/20 Festival in which thousands of people gather round the Bay to smoke weed. While it is illegal in theory in practice it is almost never enforced and one can easily find dealers with product. Indeed one can buy a medical certificate proving that you have an ailment that required treatment with marijuana from a doctor for a small fee.