The programmers that prefer creating to buying are sometimes bad for business. They may prefer to create software in-house (expensive) rather than use an existing software library (cheap). At the end of the day, a developer is only as good as the value she adds to the business.

Did you read the post your replying to? The poster pointed out that he's got other things in his life. When you grow up you might decide that $20 to spend time with your kids when they're young is cheap.

Yes, and how you spend your time is personal decision. Just because one person decides to code in their free time doesn't mean they aren't an adult nor that that's a blanket bad decision. The wording in the comment I'm responding to ("Once you grow up", "sitting on your ass in front of a computer") is kind of inflammatory and seems to imply that only non-adults have time to do coding or hacking, that it's a "kids activity", and that coding can not be a hobby (since "hobbies" is called out as another possible thing that "adults" do).

In the context of this discussion, however, if you were to ask during an interview "Talk about a personal programming project you've worked on recently" and you heard back:

Candidate A: "I don't do or think about coding outside of the office, but I did just recently spend $20 purchasing tool to upload images to flickr and I had to read the docs to configure it to work with my firewall."

Candidate B: "Well, I wanted to upload the 2,000 pictures of my son to flickr to share with my family, but doing that with the flickr web UI manually was taking a long time, and there isn't a good flickr uploader for Linux, so I hacked out a shell script that gets invoked when automount mounts my camera or flash drive that uploads the images to flickr with their API"

Is anyone seriously going to consider Candidate A, just based on this question, as more valuable for a coding/hacking/technology position? Obviously, other factors come into play, as techiferous points out elsewhere in this thread, but this is meant to show someone's passion, not if they have good judgement as to if something is worth doing (hopefully, you've got a battery of other interview questions that help determine that).

I know a lot of people like Candidate B and I would not like to work with any of them. Life is a balance. Passion for programming is good, obsessive compulsion is not.

Wow, that seems kind of extreme. We have both "adults don't program in their free time" and "programming in your free time is possibly obsessive compulsive" in this thread.

If passion is a good thing to have, how do you measure it other than with a question like this? And what would be a good way to measure unhealthy dedication to a hobby that could be obsessive compulsive?

Two reasons:

1 - it's unreasonable to not ask why saving $20 is worth many hours of your life;

2 - Why would you assume that mucking about with php and wordpress, then validating front end code in ie{6,7,8}, ff, safari, and chrome is in any way fun for the vast majority of developers?