Nobody wants an engineer who is passionate while they are literally writing code, screaming at the computer and flailing his hands[1]. Much in the same way we wouldn't want a judge to be passionate when he's handing down a sentence.
But a judge should care about our laws, our constitution, and be opinionated about them. I want a surgeon who understands how the practice of surgery is evolving and stays up to date on best practices. I want a bridge builder to get ABSOLUTELY passionate about the type of materials used on a bridge and not settle for anything less. Similarly I think the best software engineers care deeply and are knowledgable about the craft of software engnineering.
[1] Well, I've had a coworker who did this and it was actually really comical and we were all entertained, but he was the exception that proved the rule.