Well, we know how my XO feels. :)
Shawna is correct in pointing out the MUSE has always been a CPA thing. Sims in other groups have certainly had logs of the month, but the CPA may be the only one to consistently set these logs side by side and vote on which is best. It's tradition.
Traditions only work when they serve the society. Traditions are good for marking seasons, for religious and social rites, for teaching someone the morals of their society, what they would like to stand for, and give them a sense of belonging. Other than perhaps the very last (We're the CPA, look what WE have!) the MUSE doesn't really fill the other roles except arguably hinting at how to write a good log. Traditions that don't serve the society make one of two things happen: Either they fade away into history, or they make the society stagnate.
I think there's a deeper issue, and a more powerful argument Shawna could make, and it is this: Why the bloody hell are we sharing anything with a rival organization? Admiral Gem, who I think most of us know and respect, would recoil from this idea.
If you've been simming for any length of time, you KNOW the intergroup rivalry is fierce, and you KNOW most other groups wouldn't offer to share with us. Annex? Maybe. Share? Ha. The battle that brought what was then my only sim from SFOL to CPA was epic, and loyalty did most certainly come up. CPA itself was founded as a protest against COL, which was founded as a protest against SFOL. Some of these enmities are ancient.
They're tradition.
This agreement offers us a different paradigm. It implies that we're stronger together than apart. It reflects the current reality that finding new recruits for sims is hard, without conceding weakness on either our part or theirs. It simply suggests that if we find ways to work together, our players may get to know each other. If our players get to know each other, by definition that's a bigger player base for all of us. They're more likely to look at both of our schedules to fill their needs, and might convince others sick of more formalized organizations to see what the TWO of us are up to.
Put another way, we have nothing to lose except arguably the prestige of having a unique award. I don't see them draining us of players nor vice versa - our respective sizes are too close.