The problem with this policy is that it works well when dealing with individuals, but you can still be swamped by "first-time sloppers" - sure, each one cannot ever submit again because it's low-quality slop, but the damage is done.

(And in reality EVERYONE's AI policy is a variation of this no matter how strict they get, because very few people will suddenly rip all of tridge's code out of Samba if he admits he used AI once, and nobody can withstand slopspam for long.)