With the added power allowed to PCs in Unearthed Arcana, perhaps it would have been a wash.
A double specialized 10th level ranger would be dealing +13 damage per melee hit against giants, before any consideration of magic weapon or Strength bonus, for example.
With the increase in size of hit dice and the corresponding number of hit points per die, would any change have been made to the xp award per hit point? Would the monster HD damage bonus be considerered a new special or extraordinary ability? Or would it just fall under the original guidelines for damage ranges given in the XP section of the DMG (meaning more monsters would qualify for XO bonus due to increased damage range)?