What's so unique about instagram? Only thing I can think of is that it's popular. It doesn't seem to be novel from a technology standpoint. There doesn't seem to be any secret sauce for making it generate cash. What would you say, the founders did successfully after the acquisition? Given unlimited power, what could they have done?
I think the answer is not much. The founders did a good job at getting some capital and making a popular product. Mission accomplished. Time for them to move on.