How long do you need to get your feet wet? More than 1 match? 10 matches? Some people only shoot 4-6 matches a year.
They should have to get a membership after their first match if they want to keep shooting.
We have 100+ shooters at our local match EVERY month. I see the same fools shooting every month that aren't ever going to pay for a membership.
So what? Surcharge them $5 or $10 / match. Let's say the same non-members shoots 4 matches every year. At $5/ match, that's $20 / year to the org. That's almost the cost of an associate membership, and there's no HQ overhead for that fee, so it's as good as a membership since I'm guessing it costs more than $5 in admin cost to renew a member.
Also, who's fault is it that whoever runs the match sucks at economics? If a match sells out in 2 hours, it's underpriced. Period. That's a strong market signal. A rational market would respond by raising costs until the match sells out with the last walk up entry, and if it makes enough money for a range, other ranges would think "shit, I want me some of that USPSA money" and start a slightly cheaper match, or offer a different schedule.
Instead, the Fudds see guys walking around with holstered guns, shooting fast, and even worse, running with loaded guns and say "fuck, that ain't worth $5 a shooter, that's dangerous cause that ain't how we used to do it hunting rats at the crick when I was growin up."
TLDR: people respond to economic incentives. Give them one to join.