I could not agree more.
I feel the arcade is a very important branch of the site, and for anyone just browsing or curious about construct 2, it would probably be the first port of call, but looking at the arcade specific forums, and the amount of comments,proportional to games uploaded it seems few C2 users share that view.
Regarding "test modules" There is the example games section,which I guess would be the correct place for them, but I assume most would think it's going to be totally ignored there, so upload to the arcade.
I certainly think the arcade needs a spring clean to sort the wheat from the chaff, also get rid of the multiple uploads of the same "game"
But at the same time it's important to encourage people to upload and show the world, something they have put time and effort into...
Most games, if not instantly noticed and rated will be swept into the slew of bilge within days.
On paper the current system should get the better games up the ladder,with the rubbish being left at the bottom but it requires lots of users actually playing and rating to work...