As a developer, I take it as a red flag whenever I hear a prospective employer categorically state "I would never hire a programmer that X."
First of all, it's a heuristic. If a programmer doesn't program outside of work, it could be that they are not passionate and don't take the time to keep their skills sharp. It could also be that they are a polymath genius, and simply can't function unless their life is full of a variety of interests.
Hiring heuristics are appropriate when there are too many applicants. For the sake of efficiency, you need some way to narrow down the huge stack of applications. However, if you are having a hard time finding developers, that's not the time to use heuristics.
It tells me something about a prospective employer's problem-solving skills and imagination when they would not consider interviewing someone for a single reason, such as not having a blog. That's like being a one-issue voter.
Also, these heuristics have a way of confirming themselves. The person who hires only programmers who do X will probably end up finding decent programmers anyway, but they will be oblivious about the ones that got away.
What if the employer says: "I would never hire a programmer that sucks"?
Seems pretty reasonable to filter out people who are bad at their job.
So your argument is really one of breadth - breadth of the filter. From my point of view as a programmer, I certainly do believe that programming outside of your job is an extremely good predictor of passion, which is a great predictor of ability as a developer, particularly for younger people. I might consider a 40-year old who doesn't program for fun anymore, maybe. I wouldn't bother interviewing a 25 year old who never saw a point in coding outside of university/work.
"I certainly do believe that programming outside of your job is an extremely good predictor of passion"
Yes, I think that's the point. Is this a good predictor? If you are a young, single male, then maybe so. There are many other reasons besides lack of passion that can prevent a passionate programmer from programming outside of work.
Actually, no. I think that's almost the definition of a passionate programmer: there's very little that cna stop them from programming outside of work - not even a full time programming day job.
Supposing for the sake of argument that you were actually passionate about more than one thing in the world, can you imagine why someone might want to spend six or eight hours doing some of the others after spending eight or ten hours doing one?
Yep. I am. And I program, but rarely outside of work. I leave work at 5 and, when the schedule permits, I start coding again after they go to bed. This is likely to happen 2 or 3 times a month. So far I've read nothing in this thread that doesn't make the assumption of no other demands on one's time. Maybe I'd get the job if I just said, "I wish"?
First of all, it's a heuristic. If a programmer doesn't program outside of work, it could be that they are not passionate and don't take the time to keep their skills sharp. It could also be that they are a polymath genius, and simply can't function unless their life is full of a variety of interests.
Hiring heuristics are appropriate when there are too many applicants. For the sake of efficiency, you need some way to narrow down the huge stack of applications. However, if you are having a hard time finding developers, that's not the time to use heuristics.
It tells me something about a prospective employer's problem-solving skills and imagination when they would not consider interviewing someone for a single reason, such as not having a blog. That's like being a one-issue voter.
Also, these heuristics have a way of confirming themselves. The person who hires only programmers who do X will probably end up finding decent programmers anyway, but they will be oblivious about the ones that got away.