I really don't understand the reasoning of this. DRG is getting improved HP, eva and parry because... They're stopping to have their wyvern heal. I'm a career DRG and I really find this reasoning to not make any sense.
So what, are you saying you don't want to have better stats? Who cares what the reasoning is? You're getting more HP, evasion and parry. Why would you complain about that?

The reasoning, to be more specific, is that in order to help you take a little bit less damage so you don't need to waste as much time using healing breath. That combined with a stronger healing breath means less wasted time casting a spell to use it, and therefore less DPS lost. Get it now?