"The Simpsons" killed off a longtime character this week, sparking shock and outrage among its fans ... and one producer says he expects nothing less from the show's diehards.

Tim Long, co-executive producer of the long-running animated sitcom, tells TMZ ... the creative team meant for Larry “The Barfly” Dalrymple's death to hit the audience hard -- even though Dalrymple never had a big moment on the show.

ICYMI ... Larry was a background character on the show, first appearing back in 1989 during season 1, and mostly showing up in Moe's Tavern near Homer Simpson and his friends. He occasionally throws out a line or two.

Long says it doesn't matter how small Larry's role was, because characters on "The Simpsons" don't die often ... so, it's a huge deal when they do.

Tim adds he's sorry to those fans upset about the death, and the sad episode in general ... but, he says he likes that fans seemed to take it as hard as Homer and the gang did during the episode -- because it speaks to how beloved the show still is.

Plus, Long jokingly says 'Flintstones' fans wouldn't have flinched if the show killed off the reviled character, The Great Gazoo ... so, it's nice to know fans care about all the characters who make Springfield what it is.

That said, Long's telling people to stop freaking out -- 'cause it's not like they killed off a major character like Barney or Moe!!!