It seems to be a natural consequence of a bigger and more complex, centralized government. Eventually the growth expands beyond the boundaries of control of where the ultimate power theoretically exists in a representational government (the electorate). So you have these czars and agencies operating almost in a vacuum, insulated from the controls built into the system of checks and balances. When agencies like the NLRB start encroaching on Constitutionally-mandated authority of a legislative branch, it behooves of to point that out (not that it will necessarily make any difference).
The Obama Administration seems particularly roguish in this respect. There have been quite a few documented cases where the Executive has essentially told other branches like the Judicial and Legislative to basically shove it when it comes to implementing its agenda. I can't help but think if it were a Republican administration doing that the media and the legal academic community would be screaming bloody murder. But Odouchebag gets a pass, naturally.