It is an interesting tool, it would be easy to "cheat" and use the grooves they supply and build songs. I don't think it is their intention though, as noted by Andy it, like Scaler 2 can help find alternative chords to give more flow.
The other reason is if, like myself, the paws just aren't as articulate as they were, old and arthritic, frequently painful, using tools like this and Scaler 2, I can keep making noise. 😉
Thanks for your ears, time and kind words.