I had a discussion on this topic previously in this forum: Ark Encounter Sold Fewer Tickets This September Than Last September - #20 by PdotdQ
Allow me to give a wild hypothesis from a non-expert:
Many atheists do not get your point, because aside from the more philosophical among them, their value system is completely people-based. They cannot understand the idea of success that is totally divorced from people.
What is a successful organization/movement/religion/etc? In this view, it seems obvious that a successful entity is one that has a lot of influence and power over people. Thus, popularity, influence, and wealth is seen as the hallmark of something successful.
These are not the same things that measure success according to a Christian view. They are not playing the same game.