Premises and conclusion seems quite incorrect: -Build a -good- language (a good -everything-, actually) is still difficult, theory is more solid after 50+ year

Premises and conclusion seems quite incorrect: -Build a -good- language (a good -everything-, actually) is still difficult, theory is more solid after 50+ years, but design is really an art. -(G)PL are not all sequential, function based, and synchro-obsessed. One -real- problem can be the recurrent re-invention of the same ideas, when a good use of old ones can solve the problems, but this is general, not only about PL.