Back in the day, you had a simple choice; Marijuana or Hashish. Sure, there were the subsets of which strain one might prefer, if one was fortunate to have more than one strain available at any one time, but Grass was invariably Sativa and Hash was solely Indica. Nowadays, most of what you find are hybrids of numerous strains of the two varieties within the same species.
This is total fucking bullshit, man.
If I wanted to smoke hash, I'd buy hash. What I want is pure Sativa for the euphoric, psychedelic, inspirational high, and nobody fucking grows this shit anymore, because of the so-called, "Drug War".
The hybrids and pure Indicas mature faster and have higher yields, so the growers can make more money sooner with those. As a result, you end up with a market of consumers glued to the Lazyboy.