the cpu requirements for the remote play app seem pretty ridiculous, an i5(m) for a 720p stream?
You have to have a beefier machine to do this since for this to work you need either specialized hardware to handle it or a beefy enough computer that can handle such 'raw' video as fast as it does with minimal latency
They could make the decoding less intense, but that would also introduce massive input latency.
Regular video 720p streams can get away with less beefy hardware because they can afford to be pre-processed more, loaded into a buffer and optimized.
Like, for example, the Wii U Gamepad's 480p screen saturates 95% of the total bandwidth of Wireless N, because they have to do this to keep the latency down to 1ms. 480p!