Those individuals who are on top of the heap at any given moment almost always have a mistaken belief that they will remain there. They forget -- or simply fail to acknowledge -- that the ever present pendulum of life tends to swing back and forth. Empires rise and then they fall. History is a testament to this fact.
Since Team Obama, like Team Dubya before them, obviously hold this sort of belief, they don't see the dangers that their mass surveillance program may portend for their own future. They seem to believe that they are immune from its nefarious nature.
But one day -- in the near or not so near future -- a different team will rise to the top. The new team may wish to discredit the previous one. Since the NSA is slurping up EVERYONE'S communications, it means that their communications too are being collected and stored. So, if someone wants to do them in, they will have all the ammunition they need.
It might be the next higher up...or it simply may be a low level political adversary. One of numerous government-contracted "intelligence analysts" may get it in their head to destroy a legacy. Maybe it will be nothing more than an attempt at blackmail for monetary gain. It could be for any number of reasons or motivations.
All of us have a few skeletons in the closet and I bet that the members of Team Obama have more than their fair share! Would they like to see them presented to the public 5, 10 or 20 years from now? Will they defend the program then as they do now?