Interest usually correlates with the desire to learn and explore on one's own time. If you have a team of interested developers/hackers, then the lack of enthusiasm can drag the team down, both in knowledge and culturally.
This isn't always true, of course. Some developers can have excellent skill and have no interest in programming outside of work. I have a coworker that does virtually nothing outside of work, doesn't keep up with current events outside of what our group discusses, but she is a great programmer and picks up on things very quickly. She shows genuine interest in the work she does at work. She's been with us for nearly nine years. Culturally, she's different than me and another one of our co-workers in a more fundamental sense, but as part of our _team_, she is a perfect fit.
> Interest usually correlates with the desire to learn and explore on one's own time.
I don't agree. Interest in doing a good job (i.e. work ethic) usually correlates with this, but I do not think work ethic corresponds very well with interest in the field.
> If you have a team of interested developers/hackers, then the lack of enthusiasm can drag the team down, both in knowledge and culturally.
I think part of my problem with the statements in this thread is that I would never put together a team of hackers to run a business. Your statement implies a team that is interested in tehcnology for technology's sake rather than as a tool to solve a business problem.
The world isn't that binary. No one is suggesting you hire a bunch of people who don't care at all about solving actual problems and who would just screw around all day messing with whatever shiny object caught their eye.
The discussion is whether someone who is just in it "for the paycheck" will be able to solve those business problems as effectively as someone who has a deeper interest in technology for technology's sake. By itself, that's obviously not enough signal to say one way or the other. There certainly are extremely valuable people who don't code outside of work, follow new language and tool discussions online, etc. I think it's equally obvious though that such an interest is a positive signal. If you told me nothing else about two potential hires except person A writes Java at work and has no interest in the field beyond that, and person B writes Java at work, but has a Github page full of utilities she wrote in Go, Lisp, Haskell, whatever, I'd bet a small amount that person B is probably better at solving technical problems. You can't say that for sure, and any of the myriad other factors that actually do matter could break the other way and make person A the better hire for an actual business, but outside interest is a positively correlated trait.
> I don't agree. Interest in doing a good job (i.e. work ethic) usually correlates with this
I wasn't expressing a 1:1 relationship. I also expressed an example where this wasn't the case: interest in the position and the work we do, but not a personal interest outside of work.
> Your statement implies a team that is interested in tehcnology for technology's sake rather than as a tool to solve a business problem.
I just happen to be a hacker that was hired by a business. That wasn't why I was hired---I was hired because of certain qualities that so happen to be a consequence of my being a hacker, and because of fundamental interest in certain topics (which also included side projects).
I'm certainly not interested in technology for technology's sake: I'm the author of a large system on which one of the core parts of my company (the company I work for, not a company I own) is based (raters for an insurance agency), and it was made using practical, business-conscious decisions. My coworker (he doesn't identify as a hacker) is Technical Director.
This isn't always true, of course. Some developers can have excellent skill and have no interest in programming outside of work. I have a coworker that does virtually nothing outside of work, doesn't keep up with current events outside of what our group discusses, but she is a great programmer and picks up on things very quickly. She shows genuine interest in the work she does at work. She's been with us for nearly nine years. Culturally, she's different than me and another one of our co-workers in a more fundamental sense, but as part of our _team_, she is a perfect fit.