Imo you guys should change the ranges for certain divisions.
I personally feel like D5 is too large (lol cause im in it), like when I was in D3 or D4 I could see my progress... D5 -> D6 is like a freakin mountain to climb, like damn better get me ice pick and snow shoes ready boys lets gooo (don't get me wrong D6 -> D7 will be like climbing up from the bottom of marinas trench, can't wait ;D)
I think you all over estimate how "this entire community is high level players".. like yeah, maybe the ones active on the forums are...
However, if you are a nerd like me and you like to parse
http://www.flashflashrevolution.com/arc/recent.php and collect data on it, you'd notice that a LARGE number of the players that play are actually lower division, like a ton ton ton of people - you'd actually be surprised at how many people play. (Velocity if you read this PLEASE don't hide the results of the recent games page ;_; bro I love you <3)
Don't wanna release any data until I actually have a decent/accurate amount, but it generally takes approx 5-10 minutes for the entire recent games page to reload with new games
In terms of unique players I'd argue that FFR has at least 2000+ daily players, which is solid.
EDIT: Shit this is about song difficulties, not tiers... i figured FGO etc was tied to div tho