From a talk he gave last year at the ASES Summit at Stanford:
So why do founders chase high valuations? They’re tricked by misplaced ambition. They feel they’ve achieved more if they get a higher valuation. They usually know other founders, and if they get a higher valuation they can say “mine is bigger than yours.” But funding is not the real test. The real test is the final outcome for the founder, and getting too high a valuation may just make a good outcome less likely.
The one advantage of a high valuation is that you get less dilution. But there is another less sexy way to achieve that: just take less money.
I wish he would write / talk more often. He’s as readable as Seth Godin, but he often has more substance to his content.