Conflict of interest is the real question to look at before you buy. A conglomerate that has several similar brands can lead to something like Dairy Queen franchisees are facing as their franchisor combines Orange Julius, is it a good move – only time will tell.
Another issue is when a franchisor is also in direct competition with their franchisees, ala UPS. There the franchisor has very different goals that appear to be in direct conflict with their fiduciary responsibility to franchisees – again time will tell.