I have held some of the following philosophy:
I personally would encourage event directors to migrate to online sign up services - especially as the local event culture is producing "full" events.
Why? The inventory (entries) is all in one place, first come, first serve, collected, organized, verified. Many have the ticker that show how many left.
When it sells out - celebrate it! Share the news... blast it on facebook! you are already building steam for the next time, or the next event. A good event director then has a nearby event in mind to refer players to that ask after its too late, even if its a little drive.
With online sign up services:
When they are gone, they are gone. Too bad. They likely ticked down one at a time. I know in our area, if you watch - even the events that fill - usually are dropping availability 2-3 spots per day during the sign up period, not in massive batches like you might think. Weekend, weekday - same rate... strange.
Then they're gone. Maybe next year. Less face to face awkward conversations where an event director caves... and lets in another over his previous cap.
Stick to the number, stick to the plan, execute well.
I totally agree with this mentality and think that this is where the tournament side of disc golf is headed and needs to be headed. It is hard to complain about not being able to play in a tournament when registration has been up for two months and you waited until the last minute. I understand people may not know whether they can play in an event a month or couple weeks down the road, but you can always back out and hopefully the TD will be willing to work with you on that, and give you the registration money back.
I think it is unfair to the players who register way early and are looking forward to playing a particular tournament, when the TD decides to let in extra people last minute and have too many people playing. I don't think, from a TD perspective, that making a handful of last minute registering players happy, is worth annoying the players who registered a head of time, with crowded cards and slow speed of play.