Speaking as a relatively new shooter, what hooked me on the sport was shooting a couple of matches where the experienced shooters took time to offer suggestions, the ROs were willing to cut me enough slack for me to get a handle on the game (i.e. reminding me of a mandatory reload or a missed target during the run instead of just giving me procedurals afterwards), and the overall atmosphere was more about comraderie than competition.
Don't get me wrong, the shooters were competitive, and ROs required all shooters to play by the rules, but they recognized that giving an unclassified shooter a chance to re-shoot a blown stage or a few tips wasn't going to threaten the integrity of the competition between the more acomplished shooters.
On the other hand, when I first tried the sport several years ago, I shot a couple of matches (one USPSA and One IDPA) where the competitors didn't offer suggestions, ROs were more interested in giving penalties than suggestions, and competition was more important than sharing the sport with a potential member. Those matches put me off the sport for two years.