The key answer there in Alent's post is "and there's just better places to spend the talents". Reckoning is a good and fine skill. It doesn't even need to be filled fully to be good, but in general, we just don't have enough points to get everything, and many talents are simply better, so it is typically the last guy added to the kickball team. Still some find room for it in their builds.
One other thing is that it doesn't really synergize with our tanking seal as much (SoV/SoCorr), so that is something to consider.
Yes, but so would lots of other talents, and they will do a better job. It is definitely an increase, but currently, it is pretty minimal and typically other talents just provide more bang for the buck.