Because it wouldn't be appropriate to volunteer for something I no longer intend to participate in.
ahevents.org isn't used just for this single scenario. It's for all scenarios and all special events (FSO's, SEC's, Air Racing, Snapshots, King of the Hill, Heavy Metal Sundays, This Day in WWII).
It's OK, though. Volunteering shouldn't happen because of convincing or external factors. If it's not for you, then it's not for you, and that's OK.
I think it's unfortunate that you won't play in a scenario because of troubles with registration, though. I hope you fly with us the next one.