Actually it is a pretty good answer, it IS the genetics that determine hash production, amounts, quality and actual oil content etc.
Sativas have smaller trichomes then do Indicas, so you won't get as much hash from a female that has genetics, that are producing smaller sativa type heads of resin. Then you do with indicas that have bigger ones. And since there is a lot of intermingling with sativa and indica from people breeding it. You never what you may come up with.
The Thunderstruck clone for example, has larger resin heads, and is ideally suited for hash making. (The pictures not mine it's Mr. Wonder's)
Here's a shot, of the Thunderstruck clone on the left, and the Vito cutting on the right (This IS my picture). The Vito cutting was a slight herm, that produced my Wonderjacks cutting that I hold. Both plants were flowered in my fluroscent garden at about the same time and size. The Vito cutting is an example of small sativa type head hash, that doesn't produce much under HID lighting. But produces copiusly under fluroscent lights.
Genetics you must remember play a part under different light regiments, as much as the genetics themselves do.