I think Nutting is more likely to move the team at the end of the current PNC lease in 2030 (I think?) than he is to sell it. Barring a miraculous turnaround, I think the Pirates have managed to evaporate a lot of the fan support that kept them in the city's good graces over the past 3 decades or so.
On top of everything else, they've been drastically understaffing the stadium and creating artificial inconveniences which I can only assume are a ploy to ask the city for "improvement" money. I sincerely doubt the city is going to fork over money for major renovations over the next several years, and I don't think Nutting, et al could possibly motivate fans to pressure politicians after all the havoc they've wrought on the franchise. I think there's a real possibility that this situation will eventually result in a situation not unlike the Penguins/Kansas City fiasco.
Long story short...if Sens fans can't get Melnyk to sell, Pirates fans will never get Nutting to sell.