I wouldn't call Jameson underappreciated. He's as much an impediment to Peter as his is a benefit.
Sure, he won't hand his golden photographer over to the Goblin, even with a knife at his throat, and that's noble, but he also doesn't pay Peter shit, is partly responsible for the creation of at least two of Spidey's rogues, and actively turns the city against him with an unrelenting campaign of libel and hate.
Since when was J. Jonah Jameson "underappreciated" (especially in his portrayals by J.K. Simmons)? "Appreciated" in this context doesn't mean "liked," you know; it means "considered important." Love-to-hate villainous characters like Simmons as JJJ, Alan Rickman as the Sherriff of Nottingham or Snape or Hans Gruber, Louise Fletcher as Nurse Ratched or Kai Winn, etc., are plenty appreciated!