Tampa grows approximately 1.5% annually. Pittsburgh has seen a population decline for the past decade.
Pittsburgh attendance bottomed out 2017 - 2019. They used to be middle of the road prior to then. However, even when attendance was up, they would still have a fairly low payroll. This probably caused a bit of disillusion with ownership among the fanbase.
Tampa is usually in the bottom 3 no matter what the standings are.
Currently, the Pittsburgh Pirates are valued at $1.26 billion. This resulted in a yearly value change of around -1%. With the majority of baseball still raking in money, this negative value change puts the Pirates as one of only two teams that lost value over the course of 2019. The Miami Marlins were the only other team that had a negative value change (-2%).
The decrease in team value is obviously tied to poor on the field performance, poor public perception, and poor management decisions. All of these factors attributed to negative fiscal trends, including a 2019 gate revenue of $44 million for the Pirates. Gate revenue is simply ticket sales, a major source of revenue for any MLB team. This is the third straight year the Pirates experienced a decrease in gate revenue, down from $70 million in 2016.
https://www.post-gazette.com/sports/pirates/2019/10/28/pittsburgh-pirates-owner-bob-nutting-neal-huntington-fired-president-travis-williams/stories/201910280082
If I have to really evaluate the two franchises, Tampa seems to have a well run franchise that is smart enough to save money where they can. The Pirates are a horribly run franchise that saves money for the owner but can't put a competitive product on the field even if they have a recent history of developing really good players (good scouting, s*** coaching?). Seems like there is just some sort of disfunction at the top of the organization that is preventing the MLB team from succeeding.