John,
Classification is about enabling our users to find the best route. To do this, it must be possible to distinguish between important and unimportant roads on the map.
If the better roads are at best "residential" or "unclassified", then it is legitimate to classify other roads that were never built for car traffic lower.
You should try out Openstreetmap.org's routing function in different places. Especially in areas that are mapped according to the HOT standard, there will be some unpleasant surprises.