Consider the odds of rolling an 18 using 3d6. It’s 1 in 216. Like me, you probably say “Wow!” when a natch 18 is rolled with 3d6 (and an equally emphatic “Ugh!” when a natch 3 is rolled). It’s almost as if the mindset in D&D is that an 18 in any ability is somehow superhuman in nature, but when we look at the chance of rolling an 18, we realize that this is hardly the case. Think of it this way; take a large body of people you have observed in real life…High School or College, or even an arena filled with fans for a concert or sporting event. Now, think of the way you might envision a D&D character with an 18 Strength, and realize that in High School, the chances are that 10 classmates had an 18 STR, in College 140 had 18 STR, and at an arena 350 fans had an 18 STR. Not so superhuman now.
He also considers save-vs-stat rolls and other such houseruling goodness. I think the idea that the stats are actually vague isn't a new one, but we don't consider all the possibilities. The classic example is Charisma. A lot of ink, digital and otherwise, has been spilled over Charisma not being a measure of physical beauty. But there's no reason why a high or low Charisma score can't be impacted by a character's physical appearance. Is your character's low Dexterity score due to being clumsy, or being nearsighted? Since Dex covers hand-eye coordination as well as balance, a low score could be due to deficiencies in either. Or both. Or even something else all together.
Anyway, it's interesting stuff to think about, especially in terms of character generation.