You miss the point.
From the standpoint of someone from the US East or West Coast; or almost anywhere in Europe, the entire state of Wyoming is "rural". Even the urban areas are rural. The most populous city has 60,000 residents. The same can be said (to a slightly lesser degree) of Montana, the Dakotas, and Idaho. And then a whole slew of additional western states outside of one or two large cities per state.
You are proposing that these entire states, and their citizens, don't matter. That we can ignore them entirely when it comes to policy because they are outliers. Twenty percent of the population and half the landmass- irrelevant?
The dense urban areas of the US do have public transit. Even Cheyenne, Wyoming has six bus routes (closed on Sundays and holidays).
Many Europeans fail to grasp that items on a national policy level in the US are akin to a EU-wide mandate. Should Estonia and France have an identical transit policy? The state gasoline tax is nearly 50-cents per gallon in New York and California, as compared to 14-cents in Wyoming. The federal tax is (an additional) 18 cents. Europeans like to ignore the state-by-state issues entirely and paint the US with a broad brush.