Revenge of the Lispers

I think that part of it may be that machines have grown more powerful. You used to compile code because you wanted that last 10% (or whatever) of performance out of your system. Now, the machine is powerful enough that you don't care.

You especially don't care if you're creating a web service. You may have to buy another machine to handle the load. But that costs, what, $500? How much programming time is that worth? Less than a week for a cheap programmer; less than a day for an expensive one. If Lisp (or FP) gets you there faster, it may well be worth the runtime inefficiency.