I wish it were easier to sort the "all" category on BGG by rank over a specified timeframe and not all time.

I suspect that if you could sort by the past 5 years, the number of covers in the top games list that have humans but no women would be low. The trend has been to either not feature humans or to feature a group of humans with diverse representation.

We use Wingspan as a test case all the time when discussing games. Would we in 2017 have signed a game about birdwatching? Honestly the answer is probably not; not because it was designed by a woman but because our perception would have been that the interest level in the market would have been non-viable. That goes exactly to your point about the challenge of a monoculture making decisions about what games to make or not make based on their (limited) personal preferences and it also speaks to why the industry is rapidly working on increasing diversity at the decision-making levels.