If a meat that contains fat is refrozen the fat within the meat may potentially cause the meat to go bad. More the most part all of your meats will have some fat in them. If it was already frozen once and you go to refreeze it again it may make your meats rancid. I don't know about you, but I don't want to eat rancid meat. And I definitely do not want a good cut of meat to go to waste.
Another reason is refreezing previously frozen meat will impact the texture of the meat. You don't want to ruin the texture of a good cut of steak. So, do not freeze previously frozen meats.