This has been discussed and suggested that TNA do for a long, long time. It's nothing new. I think Dixie Carter recently said that the money they lose each time they travel for tapings prevents them from doing it more often but ultimately they want to be in a position when they can make money on the road for TV. For now they're trying to expand their fanbase in the comfort of the Impact Zone before they set off around the country. It's sensible not to rush it imo.