I think last summer we saw frisbee run the last of its course, unfortunately. Honestly, I was thinking about sending out an email to that effect. But I just don't care to deal.
Summers during and shortly after high school, it was extremely disorganized, and we only played maybe once a week. Most players were of the same skill level, and very little attention was paid to strategy, or rules, or winning. I remember most of the games consisting of me throwing it as hard as I could, and regularly tackling people (not violently, but still). As people started playing during college, or in official leagues, greater enforcement of the rules set in, but we still played with a "for fun" mindset. Additionally, everybody was a student, with lots of time on their hands.
Now, two years into having an email and calendar organization system, we have a number of people (not myself) that could well compete in a league, combined with people who purposefully throw the frisbee in order to get it to roll unpredictably (and in turn, slowly ruining the frisbee, and pissing off the opposing team). That imbalance, and a frequent misunderstanding we're there to have fun, and not really to compete, has probably undermined our ability to attract new players.
It was also a pretty severe mistake to have frisbee twice a week last year. Our largest turnout for the entire summer was our very first game, likely due to frisbee's perceived scarcity after the winter months. After which, our turnout halved, and then dwindled as scheduling conflicts, injuries, and other obligations took regular players away. For those on the fence, having the choice of two nights in a week meant that people had the option to skip a day if they wanted to just play once a week, which meant that while we had the chance of playing two games, it meant that it decreased our chances of having enough players on both nights.
Also, I understand that people like the game well enough, but compared to other summer sports (soccer, volleyball, baseball, hiking, biking, rafting), it will always play second fiddle. Slightly more skilled as our games may have become, we're still not playing competitively, or as one would in an actual league. And for some, that makes the game extremely boring, and irritating. Without stakes, there isn't much of a reason to play, and without a reason, people tend to lose focus, and generally don't try to get better (see: taco-ing the frisbee guy).
Anyhow. I don't see the trend reversing. People have work, lives, families, hobbies, and things they'd rather be doing than show up for frisbee. As I've said, the email list (penultimate-frisbee@googlegroups.com) is still available, though I can't speak to the maintenance of the email accounts subscribed to it. If folks want to try for pickup games, feel free, I'd love to play, and usually I have all the time in the world. But I am not going to be doing the weekly invitations any more.