As the other response says. The FAQ provides some rationale & makes it clear you can, actually, build robust software with picolisp's model of scoping. My understanding is, ``dynamic scoping is faster for an interpreter'' and ``funarg is easy to avoid and closures are possible''.

See the three following points:

http://www.software-lab.de/doc/faq.html#dynamic

http://www.software-lab.de/doc/faq.html#problems

http://www.software-lab.de/doc/faq.html#closures