As someone who lives in rural Wyoming, homes like this are an incredibly tiny percentage of the overall population.
I'm not sure why you combine satellite/DSL as those are pretty different. Your comment about topography causing interference makes me think you are referring to wireless Internet, which is common in rural areas and what we use and definitely is impacted by topography.
If dial-up was previously available, often DSL is now, though not always. And satellite is basically available anywhere but is expensive and slow.
Typically when a rural house doesn't have Internet it is because the owners can't justify the cost for poor to mediocre service. For example, a grizzled, 80 year old, retired rancher doesn't care to spend $100 bucks a month for slow Internet service he never needed previously.