I go to Montana's because I don't think I could personally make a burger that tastes better, I go to a pizza place near where I live because they have some of the best pizza I have ever had. Every sandwich I have gotten from Subway feels like a regular sandwich that I could have easily made. I don't hate Subway, but I don't like eating there either.
Tbh if I went out somewhere specifically to have something nice to eat, I wouldn't get a sandwich. I see what you mean, but I view Subway not as a "nice" place (though I still think they are delicious, but that's just my opinion) but as somewhere to get something quickly (i.e the microwave meals of food outlets) if you are out, say, shopping and are feeling hungry. Depending on what you get, it can also be healthy.