In the context of a job hiring candidate, I'd consider "passion" and "enthusiasm" to be synonymous. The idea would be to imply that you're interested in building cool things and solving difficult problems more so than just receiving a paycheck. And that's a beneficial thing to convey as a candidate regardless of your age.

Regarding training someone for a new stack: You quite possibly are right. I just think it's possible for employers to disagree with your view and not be presumed "-ist."