You are all missing the real purpose of the changes to hit and AC, and it has nothing to do with skilled or unskilled players.
The new system supports many more builds than the old system does.
The amount of pure tanks out there is so small that I find it hard to believe turbine cares, and nor should they, about the difference between the players who wish they were tanks but dont know how to build them and those who truely are geared and built properly as an AC tank today on live.
The new system means you dont have to invest 100% into AC to get usable end game AC. In the current game system AC is worthless at end game for the vast majority of character builds, REGARDLESS of their skill. No matter how you look at it, that is not a good design. PnP was never intended to have players running around at level 20 in full +14 equipment.
The absolute greatest thing about DDO is the versatility available in character builds, and this change increases the depth of the vast majority of possible character builds while slightly harming some very few builds.
Is this the best possible solution to the problem? Probably not, at least I think a better system would be making the mitigation curve linear in regards to time to live (e.g. The same amount of AC it would take to go from 0% to 10% avoidance would be the same as from 50% to 55% resulting in AC always reducing the same percentage of incoming hits at all times) regardless, whether it is the ideal choice, it is still much better than the current system in live.
You don't have to be a bad player to not want to play a full AC tank yet still wish AC could actually mean SOMETHING.