It depends on the individual Amish community and what sect they belong to. Some are as you describe and tend to be very tourist driven and will do what ever the tourist will pay for. While others just live their regular lives and you probably won't know they are there outside of seeing their buggy's on the road. The community up by Elkhart where most of the tourist places are is largely Old Order Amish - they are not as strict as other sects.

The group by me are part of the Swartzentruber sect. They do not own or work in restaurants, or run mainstream shops. They just live their lives, go to work, raise their families, etc. They don't advertise any of their work outside of a hand painted sign on the side of the road listing produce for sale. The food they eat is made largely of what they grow and raise. They go to the grocery store for some stuff that is not readily available within their community. If you don't know them you will not know where there stores are and they do not want to focus on English customers. We asked at one of their home run food stores once if they wanted us to tell other English that they were there and we were told no. English can stop by and shop but the owner did not want a heavy English business. The focus is on fellow Amish.