So, culture aside, there are some other aspects to consider. One is simple economics; if you make the dish at home, you are somewhat or even very much less likely to go buy it at the restaurant. Someone has either invented or adapted a very nice dish that you liked, and you're cutting them off from the benefit of your own business. Especially if it's a small or independent restaurant if we want practitioners of the craft and art of cooking to keep doing it, it's good to support them financially.