But I'm not just talking about blind, unfocused and overly enthusiastic passion. I'm talking about the passion that drives people to go beyond the call of duty, not because it is part of the job but because it is what they like to do. Passion got me the job I have now. Although I was also more than merely competent, the passion drove me to achieve that competence in the first place.

Even if they're building important capabilities for a team's core product, they're doing it in a way that is basically impossible to schedule, on timelines that are impossible to reason about, because "passion" is idiosyncratic.

Yeah, passion is a bit of an x-factor, isn't it? By itself, it is meaningless. You may get something unexpectedly great or unexpectedly bad. But, using myself as an example again, I was able to get a project at work done well ahead of schedule because I had already been working on something related in my spare time.

Passion (about what? quality? new technology? learning? building things? these are all different things) doesn't hurt anything. It's not a bad thing. It might even be a good thing. But it is not a crucial attribute of a new hire on most teams. If you need passion, consider whether you're hiring cofounders, not teammates.

Inasmuch as someone is proud of a project they did and can talk enthusiastically about it, and that project is related to work currently going on at the company they are applying to, I think a passionate candidate can be better long term than another candidate that is initially more competent and more effective. If experience is the main reason that candidate A is more competent and effective than candidate B, then candidate B may eventually surpass candidate A as a better employee simply because passion drives candidate B to keep honing his skills in his free time. I think this is especially true for college graduates or other junior candidates who may not have anything else to go by but their projects.