Literally the only way to improve the Arena is to add more people to its userbase, because people fall into a malaise when gameplay gets repetitive. Small groups work for organized roleplays but not everyone here has the same tastes. 

So push comes to shove, the Arena is dead because of Guildfall. A ton of old players from before then never came back, and those that did have slowly drifted off. Leaving behind only a few players from back then, and the stragglers who stumble upon us. Those people that do stumble upon us wind up leaving too, because the community is so small. When they've grown bored of us, they'll duck out.

It's an infinite cycle perpetuated by boredom.