I don't think this is a bug...I think it's intentional. It's designed where, unlike tournaments, there is no 'participation trophy' just for showing up. It's also intended to require the same amount of effort from all (or almost all) FS members to get the most out of the FS rewards. In tourneys, a few heavy hitters can get the 10 chests and everyone else can benefit from their work. It takes 21 players going to the top to get the Gold Trophy. Of course, if 25 members play, slightly fewer would need to reach the end for those that do get there to receive those rewards.
I think your problem is the effort put in by the rest of your FS members. No one is required to like the Spire or go all in for all the rewards. But when one player wants to do that and the other FS members do not, I think that's the definition of 'not a good fit' instead of the definition of a 'bug' and doesn't necessarily mean the feature needs an adjustment.