I support this change, even though I dislike horse archery and the people who use it as a playstyle.
From the standpoint of game balance, the weakest class that wasn't explicitly a joke/gimmick build before the recent changes to archery was a high strength (27+) foot archer; now that strength archery is viable in its own way though, that title probably belongs to horse archers. There is currently very little reason to be a horse archer rather than a horse crossbow, unless you are a masochist or want to roleplay being a mongol that much, because, as a class, horse crossbow has better performance in nearly every area and is easier to play as well. Anyone who has spent time with both can confirm this.
Like everyone else, I really don't want to see horse archers two-shotting people while flying across the battlefield with the speed and maneuverability of an F-22, but I would not be against throwing them a bone as long as it remains a difficult class to earn kills with and doesn't become the new flavor of the month.