Apart from the lying and profiteering, there’s the issue of animal welfare and people’s health. Horses are slaughtered in knackeries, not in abattoirs (which supposedly only slaughter animals for human consumption). Knackeries must comply with their state or territory animal welfare legislation but every state differs, so if there is horse meat in your mince you do not know under what conditions in was slaughtered. If you want to know a little more: https://www.farmtransparency.org/kb/food/knackeries