On larger bodies of water, this isn't so bad, but those little rivers are nothing but trouble (and Gnomes have it even worse). Even cowboys knew how to ford with their horses -- why can't we do the same with our mounts?
Zarhym, the new CM, doesn't seem very empathetic, so odds are that this won't change anytime soon. We can only hope that in future designs, Blizzard stays away from putting the deeper water all over the landscape, where it acts as nothing but an annoying roadblock in front of our next quest. It's not like we don't have enough problems with the water as it is.