After they're programmed for 20+ years in the language, and with them considered job offers or projects based on the language use, when exactly it's not considered "married"?
Easy to test on a case-by-case basis -- either a person can or can't drop one language and become productive in another in a short time. If they can, then they're not married to a single language, unlike cybernetic swans who mate for life.
Yes, true, but they're not married to their choice.