My assumption is that it's less to do with the time of 3:53 run by Webb and more to do with the way the 3:53 was run - destroying the record, in a pro field at the bowerman mile, and well before spike tech - that makes it live in infamy. Also, that many have tried, but no one has gotten close since.
While everyone is impressed with the new high school girls record, is there a mark that a girl could run to give everyone the same feeling of awe that Webb's 3:53 did and does?