There's somewhat of a balancing act that DMs have to do to accommodate we players, especially with quest series. Too open, and it gets overrun by players who lust after quest xp and don't care about the rp; too closed, and it feels exclusive and cliqueish. Too wide level range allowed, and players feel either intimidated by, or bored by the challenges; too narrow, and everyone outside that range feels put off. Too short sessions, and there's a higher likelihood for stopping in the middle of a cave, meaning the next session will be closed; too long sessions and people won't come because they can't commit that large an amount of time.
It took me a few months before I was able to go on my first quest, so I understand your frustration, but there have also been a few times I've gone on three in a week.
I agree with you, it can be frustrating to look at the calendar and get excited when there are events that math your schedule, only to realize that they are all closed sessions, but I can hardly begrudge those involved. I personally prefer to go on quests with a smaller cast and a narrower level range, so I enjoy them when they include my characters, and I can't complain when quests are limited to exclude me.
After well over a year here, I still have attended very few of the longer series, because my schedule is erratic, and I don't feel I should be a part of them when I can't commit to be there semi-regularly. So mostly, I play in some of the one-shots that people run, which I highly recommend, especially if you are new to layo quests. Although longer series offer a certain scope and impact that shorter quests and one-shots can't manage as well, the shorter quests tend to be much more accessible. a few DM's run regular one-shots, in various timezones, so you might want to check those out.
