A good programmer will write good, readable and maintainable code in just about any language. And on the same account, any language can be abused to write horrible monsters.
And what you keep leaving out is that average programmers, the common case, will likely write the kind of code that the language encourages them write. All your hand-waving about how its possible to write good, readable structured code in TRS-80 BASIC (which is true) is only trying to distract from the reality that a quirky language that prides itself on its TMTOWTDI anarchy will likely reap (has demonstrably already reaped, actually) what it sews when average programmers get hold of it. And when they leave the project, their replacements, good, bad, or average, have to deal with the mess. That makes languages which encourage writing
unmaintainable code a hazard to all programmers: good, bad, and average.
BTW, I think a couple of us here are still waiting to see the evidence to support your claim that Python's PostgreSQL modules use popen() on psql.