First off, this is not a city vs rural issue. It is a gray area of criteria issue.
I hope Niantic will answer you here. I have been begging for a clarification on these.
For your nomination, consider if the builder’s marker there is a great place to socialize? imo no. Is it a great place to exercise? Again, you may walk past it, but there is nothing inherent in the sign to attract you there for exercise. Is it a great place of exploration? Would you take a friend over to come check out the neighborhood sign? I think not. imo this was correctly rejected.
Things get accepted incorrectly way too often, and then are difficult (to impossible) to get removed. I addressed a similar Featured Wayspot quite a while ago, but Niantic still has not weighed in on that one.