Lisp is perhaps the most powerful language there is. But no language is 'too powerful' considering the software that is being built today. It has not enjoyed commercial success because it gained reputation as an inefficient language and the average programmer cannot become proficient in it unless he has a certain amount of discipline and learning he is prepared to invest. C and C++ are much easier to learn and are taught more in colleges. So the reason lisp isn't popular is because people are not learning it. And even those who learn it have less opportunities to use it because of the C, C++ and Java legacy.