Liberty Scott points out that protection and subsidies incentivise the meat cheats:
This is fraud, and should be treated as such. However, secondary to this are the market distortions created by the Common Agricultural Policy. Meat moves freely and tariff free within the EU. However, the EU imposes strict quotas on beef from outside the EU, such as a limit of 1,200 tonnes a year from New Zealand. It also imposes a 20% tariff within that quota. Although it allows outside quota beef in, it must have a tariff of around 100-250%. All NZ beef imported into the EU must meet strict labelling and traceability conditions, unlike the subsidised EU beef.
Horse meat is widely eaten in Europe so it might not be a food safety issue though it does call into question the effectiveness of strict food labelling requirements.
Whether or not it’s a food safety issue though is no excuse for fraudulently labelling horse meat as beef. However, there would be a lot less incentive for this if the EU had freer trade with countries outside its borders.