Why are they so confrontational? Why is a substitute working a significant game in mid-August? Why are they so reluctant to ask for help?
Part of why the reaction is often so vehement is that baseball umpires are actors in the game in a way referees in hockey, basketball and football are not. After all, you rarely hear anyone yell, "Kill the linesman!"
"In basketball, if you call a foul on one end, you go to other end, call one the other way, and it's all squared up," said Larry McCoy, who umpired in the American League from 1970 to 1999. "The game kind of flows from one moment to another. It's kind of that way in football, too. But in baseball, when there's a close call, there's an argument, and the game stops. Everyone's attention is on that umpire."
"Every play in baseball," said Marty Springstead, who umpired from 1966 to 1985 and then served as a major-league supervisor, "the umpire is making a decision."
And if that umpire is wearing a non-conciliatory, tough-guy, Joe West-like expression, everyone assumes he's just spoiling for a fight.
"That's not so," Springstead said. "But you do have to let the 50 people in the dugouts and the 50,000 people in the stands know who's in charge. It's four against 60,000 when you're out there. You'd better be tough."
According to McCoy anyway, despite the perceptions, there are fewer smirking umpires itching for a fight than ever in baseball.
"That was old school," he said. "When I was working there were less of them than 20 years earlier. There are even less now. But you've got to do more than project toughness. You've got to be tough."