Lived in SoCal for a long while and have family in Germany. Have had access to inexpensive and incredible Mexican food. There are a host of cultural and economical reasons as folks have laid out already. One problem in particular is the cost of masa harina. It is incredibly expensive in Europe. One of those things where if you want it, you have to make it yourself. I recall a Jamie Oliver taco episode, I was appalled at what he made. His audience for this show was UK, it seemed. Should be against the law to call whatever that was tacos.