Well, we don't know that it hasn't happened this quarter-century; we just know it hasn't happened famously.
Fair enough, but I'd say we *do* know it didn't happen famously in the first twenty years of the past twenty five.
I've read a few more pages since my post. Smolin found MOND intriguing. I wonder what he thinks now given the unfavorable observations in the few months since his book as published.