Don’t understimate non-technical factors! There’s no question in my mind that Lisp is strictly more expressive than Smalltalk. And in the project I work on (Croquet), some of the key people are probably more proficient at Lisp than Smalltalk. And yet there are other factors…. For managers in “the enterprise”, the key factors are risk/predictability. Suppose some project can be done in two weeks with 2 really good Lisp/Squeak cowboys, but in in 20 weeks with 10 completely commodity programmers. And suppose that all projects, regardless of duration, always turn out to be +/- 8 weeks of estimate (often due to non-technical factors), and 50% of all project fail no matter what you do (pick your own favorite percentage). Now, if you play poker, which bet gives you the best odds of making your goal within 25% of your estimate?
While one can question the numbers, it’s hard to question the reasoning.