I would say anyone with season tickets, who donates, who buys official PITT merchandise, who attends most of the games is a "diehard+" and in the PITT dictionary under F for Fan.
If you do all of the above and drive in for the game and return home that night you're a "diehard" ++,.
If you do all of the above, drive in from long distance, get a hotel, eat and drink locally fueling the local economy you're a "diehard "+++
Most on here don't do any of those things but post thousands of posts each year critical of PITT.
Those people are "losers" in the PITT dictionary under L for Loser.
They should go to G in the PITT dictionary for Go, and A in the same dictionary for Away and put those two words together Go Away combined with Loser!