Because - as an anthropologist with more than a passing interest in paleoanthropology, which is the correct term (archaeologists go gooey over buildings; caves are not buildings; turf fights are avoided) - it's not unreasonable to date the dawn of true humanity, regardless of brain size, fire making, tool usage, or anything else, to the beginning of the impetus to create art. The sheer cognitive leap between the thing and the symbol is huge, bigger than even fire - because without that, we wouldn't have symbolic language. Our conversations would be limited to talking about real things that we could touch and had with us at the time, and articulations of alert, such as might happen if a wildebeest crashed out of the brush toward us.

The idea of whether cave drawings have professional merit frankly turns my stomach. They represent a lot more than that.