Well, they've only played the finals in 3 NFL stadiums.
Still a bit too regional of a sport I guess to move it around more. But Hartford is a good location and should get good crowds. I suppose the NYC or Charlotte areas might have enough of a lacrosse base to have success there. But even in Pa where Philly is, lacrosse at the high school level is generally only played in the eastern part of the state (Harrisburg and east) with just a handful of large schools in the Pittsburgh or Erie areas being an exception.