As I understand it, the first change to turn Holy Shield into 5% block chance was just the first half of what they wanted to do. Imagine that the second half was giving diminishing returns to block chance, which would mean Holy Shield would be rather valuable as a source of undiminished block.
We just never got to see that part because they had already changed their minds by then.
Then, the second change to turn Holy Shield into its own button and removing our passive 10% block value was a result of the conclusions that they offered at Ask the Devs: That their initial plan to change Mastery more drastically (to make it harder or impossible to cap) would have required Paladins to re-gem, re-gear and re-forge, which they felt would be too punishing for the players.
So, they went with this other change that does not hit our stat weights so much, "delays" the problem for at least another tier, and also hits their goal of shifting a bit more defensive responsibility into the hands of the player himself.
Several birds with one stone.
It's possible that they'll look at Mastery directly again, but that's probably not in the cards until 4.3 or a 4.2.1 at the earliest.
This was very well put, and leaves me with little more to say.
The reality is that Blizzard is both largely competent and largely honest, and sometimes they just disagree with you about game design. They might be wrong - but in that case your energy is probably better spent trying to show them how they're wrong through argument than suggesting that they're lying/deceiving us.
Without a doubt.
It bears repeating that game designers, producers, developers and executives read threads like these. When a conversation steers away from discussion about the game and into assertions about motives, that can cause them to move on to another thread.
