Um, I like technology and music so why not?
Because .midi's just a set of instructions (ie the "sheet music"), and the only reason we can hear it is because our computers have default sounds for midi files.
Now if you're planning to add this to some game or project or something that supports midi, then that's fine, I just think it's odd you're composing a song in midi just for the sake of it being midi.
You're not very smart, are you?
wat