A percentage of them (like me) are other explorers and are looking for venues and clues as to where they are. Others are vandals, thieves, arsonists and spray painters. I get few engagers and barely any likes. The one below is a really good one concerning numbers (but a shit explore!).
On HIVE, I know the readers are NONE of the above things. If it's not instant gratification on FB, few bother.
Why do I bother? Because it exposes HIVE a little to the masses. Occasionally one makes it over and sticks.