Because the MIDI is getting converted to audio outside of the computer. You could just record the synth to the audio track, but then it's all mixed together into one audio track.
I like keeping the sounds separate until final mix. Drag/drop feature should make it quick and easy. Drag the whole combo over to DAW.

The term 'render' implies using a softsynth inside the computer.


I do not work here, but the benefits are still awesome
Make your sound your own!