I'd like to observe that, prior to the NEC gettint involved in this matter, 'tamper resistant' trceptacles were addressed by other codes, other agencies, typically requiring them in day care centers and such.
Even then, the rules typically specified a distance (within reach of the little ones), restricted the requirement to areas used by the children, and perhaps removed the requirement if the circuit was FCI protected.
Most of the proposals submitted to the NEC panel restate these requirement, extending the NEC requirement into commercial locations.
The 2008 requirement was resisted primarily, I believe, because it took everyone by surprise. We can add to that a general cynicism (if it can break, it will), and concerns about servicing receptacles.
After all, just how do you test a receptacle. Now the things are specifically designed to keep your meter probes and ticker out!
There was also the broad scope of the 2008 requirement. No matter how inaccessible, or out of reach of children, the code requires the receptacles to be tamper resistant.
I started these threads - and there will be more - to encourage discussion and comment upon these, and other, proposals to the NEC. If you don't like a proposal, now is the time to speak up.