I don't see the big deal of 1 in 40 HH members being diamonds. It's not like all 162,500 Diamonds are staying at the same property on the same day. I imagine that even at the most popular hotels on the most popular days, the percentage of guests who are Diamonds are under 10%. On a day-to-day basis, I'd bet only 1 or 2 Diamonds are present at a property, if at all.
Same with Golds.
What you need to worry about is people like me. Silvers (now Gold thanks to the "Stay 4 get Gold" HH promo) who, when on vacation, actually book and pay for an Executive Floor room, instead of hoping for/expecting an upgrade.