Tyrone supporters would be visitors to the Republic of Ireland and would, therefore, contribute to the Irish economy. By contrast, the Kerry supporters who travel to Dublin are not adding to the Irish economy. They are spending money in Dublin that they could otherwise spend in Kerry. Dublin's gains are Kerry's losses. Unlike Tyrone, both counties are part of the Republic of Ireland.
It is not an argument the GAA would make. The troubled history of the island of Ireland makes it an uncomfortable argument for many GAA people. I made a similar point to a prominent GAA person a number of years ago. He replied, "John, we don't see it that way."