Simply put, let's say HT puts in the effort. New guy logs in, sees
Melee arena (89/1000)
Mouse Only Arena(5/1000)
Was it worth it? If a change can't be integrated into the MA, a side arena is unlikely to be able to hit critical mass for fun. Heck, depending what people are up to, sometimes the MA doesn't hit critical mass for fun for people in the air.
Wiley.
That's one possible outcome.
Another might be, the new use is detected as only having a mouse and a dialog box pops up welcoming them and suggesting as a mouse-only user they first try the Mouse-Pilot Arena. They see that dialog before they even get to the normal clipboard. In there they can fly in a reasonably level playing field against other mouse-pilots and you could even populate the with additional AI targets that are toned-down to mouse-pilot appropriate levels. They might also then go try the melee and get slaughtered helplessly. They can at least go back to the mouse arena and so maybe they won't leave completely within 30 min.
Keep in mind, you probably are seeing more mouse-only players
EVERY MONTH, MONTH AFTER MONTH, than there are current subscribers total.
If 10% of those give the Mouse-Pilot Arena a try, you might see:
Melee arena (89/1000)
Mouse Only Arena(300/1000)
Maybe some of those will stay for a full two-week trial. Maybe they will tell friends about a fun game they found. Maybe some will decide to also buy a joystick and try the melee.
Maybe some will subscribe.