There were a lot of good ideas explored in Lisp - but not always they were first developed in Lisp (for example OOP came from Simula and Smalltalk to Lisp and merged their with Lisp approaches). Many ideas developed in Lisp have not even been reused now. It is buried in computer science reports from 60-90 (which no one reads anymore) and code which has been lost (or is not accessible). Example: Lisp 1.5 from the 60s had a bitmap used for marking objects during GC - Ruby 2.0 just now implemented this thing. One could have read old Lisp implementations from the last 50 years - but this is not how people work. Few people study old stuff and harvest it.
The flexibility of Lisp to change the language in multiple dimensions is still valid. There are few languages which provide it in a seamless and built-in way. That's why some people still use Lisp. It's also a thing which limits Lisp: it is more difficult to understand and goes against the coding standards in 'enterprise software development'.
The flexibility of Lisp to change the language in multiple dimensions is still valid. There are few languages which provide it in a seamless and built-in way. That's why some people still use Lisp. It's also a thing which limits Lisp: it is more difficult to understand and goes against the coding standards in 'enterprise software development'.