Regardless of how cheap things are, some people are minors or do not have any income. Some people use laptops which have to have the whole system replaced in these types of circumstances.
15-16% of the market still runs non-DX11 cards according to the November steam polls. Most games that run DX11+ still provide a DX10 option.
As I said, it does not affect me directly, but that's still a pretty decent chunk of the playerbase. If you look at a cross-section of 10 players who own Divinity, assuming they fit the norms, then 1-2 will be unable to play as a result of this requirement.
