The programming language can have definite business impacts. It can impact hiring, salary costs (if the skill is rare), ramp-up costs (if it needs to be taught), etc.
Even bus-factor comes into it.
Even bus-factor comes into it.
I don't even want to recruit or be recruited with such a title.
If the company is using Common Lisp, do you have the 6-12 months to wait for them to ramp up, or do you hire someone who has done Lisp before? That is downstream from the technical decision to use Common Lisp, but it is a huge business impact.