Noteflight’s luddite manifesto, in which they creatively forget about MIDI composition.
By comparison, audio is a frozen, static record of something that was played once. You can remix it, resample it and apply effects to it, but its musical DNA is a done deal. An audio recording contains the same ideas that could be written down in notation, but the recording is already telling you, “this is how it sounds.” In contrast, a score asks a question: “how could this sound?”
Synthopia has a nice rebuttal.
Also of note, from the Noteflight FAQ:
Can I enter music into Noteflight using a MIDI keyboard, or play Noteflight scores back using my own MIDI instruments?
The Adobe Flash Player Plugin, which is used to run Noteflight’s Score Editor, does not have access to your system’s MIDI devices. We are working on various technical approaches that would allow MIDI devices to be used with Noteflight.
Instead of writing manifesto’s defending an antiquated trade, maybe they should be looking a little more seriously into MIDI keyboard support.
WILL KUHN 
Oh dear, the misunderstandings abound! I am in love with audio, electronic music and MIDI (and I agreed with many posters on the Synthtopia thread). I’m only making the case for a balanced diet in our musical culture, not trying to reject anything.
By the way, we are currently beta testing MIDI support on Noteflight and expect to release it shortly, towards further perpetuation of an antiquated trade — the trade in MIDI-enabled instruments, that is. OSC over Bluetooth, please!