Pejoratively referring to people as "pedants" simply because they know what they are talking about is quite the ad hominem fallacy.
As for what people care about, it depends on what they're doing and what they know about the input distribution. If you're concerned about DOS attacks or response time in a game, then worse case is of primary importance. But if you're paying for wall time then you measure a hash table lookup by its O(1) average time, not its O(n) worst case time.
As for what people care about, it depends on what they're doing and what they know about the input distribution. If you're concerned about DOS attacks or response time in a game, then worse case is of primary importance. But if you're paying for wall time then you measure a hash table lookup by its O(1) average time, not its O(n) worst case time.