Nations spend hundreds of millions, and in some cases billions, of dollars to secure their networks.
At what point does it make financial sense to code your own operating system and application suite that instead of using consumer grade crap?
None of the current vendors have shown that device and network security is the most important item. For anyone that thinks network security isn't possible: you're delusional because it is. What isn't possible is leaving it up to entities that base decisions on how much it costs them to clean up afterwards.