I saw it expressed by multiple people whose language of choice was Lisp but the only one that I specifically remember is Ron Garret’s recent post called Lisping at JPL Revisited[1]:

  All this is a reflection of the so-called Lisp curse, the fundamental problem with Lisp -- its great strength is simultaneously its great weakness.  It is super-simple to customize Lisp to suit your personal tastes, and so everyone does, and so you end up with a fragmented ecosystem of little sub-languages, not all of which (to put it mildly) are particularly well designed.

He doesn’t specifically say here though that this makes Lisp a solo tool. I can’t find a source for that right now unfortunately.

[1] http://blog.rongarret.info/2023/01/lisping-at-jpl-revisited....

Mainly, the online opinions of people who have no Lisp experience, solo or collaborative, but have read something to that effect somewhere.

Lisp is the most powerful and elegant language. That is a problem because you're giving weak, fallible monkeys phenomenal cosmic powers. Now, many monkeys are well-behaved and disciplined, so they create reasonable, pleasant codebases. But some monkeys go bananas.