This also leads beginners to overestimate themselves, resulting in piles of live, insecure PHP code.

Just because it works, doesn't mean it's good or secure. And while it's very easy to see if something works or not, it's very hard to see if something is secure.

I think you indicated the problem. You can be secure or insecure in just about any language, but the barrier to entry is so low in PHP that it is easiest for beginners to do a lot of damage while still launching an app.

I’d rather there be some learning curve so people understand what they’re doing (or not doing).

> PHP is also easier to get started, easier to understand and easier to modify. So it's a trade off.

And as a result also easier to achieve proficiency in.