[tuukkah]

Yes, programming languages and programming are very limited when compared to natural languages and the range of typical verbal communication.

The fact that at least some older adults do internalise new languages and become undistinguishable from native speakers begs the question why everyone cannot. I'd say plausible explanations include adults being buzy or lazy with their lives, having a fixed mindset towards language learning, bad pedagogy etc. as alternatives to loss of the necessary plasticity. All these can apply to learning programming likewise.