SRAM didn't drop the ball. The XD driver is so you can have a 10 tooth cog on the 11spd cassettes and keep the gear range of single ring drivetrains closer to a double.
A 30t chainring paired with a 10-42 cassette gives you almost the same range as a 39/26 double with an 11-36 cassette. You only lose the tallest (39x11) gear. With an 11-42 your tallest gear is still lower than 39x13.
The road 11spd cassettes are not aimed at single ring drive trains, so the 10t cog was not a priority. Most 11spd cassettes keep the same range as 10spd, they just have closer spacing between the cogs.