Sure there are programmers that don't program in their spare time that are great programmers, but I think the general theme is that doing side projects in your

Sure there are programmers that don't program in their spare time that are great programmers, but I think the general theme is that doing side projects in your spare time is generally a strong signal you're adventurous, self-reliant, eager to learn, interested in broadening your skills and have a strong desire to get better -- all very important things in anyone hoping to get better at your craft. When I'm interviewing people, side projects (especially successful ones) are _strong_ signals of a candidates value as a good programmer. This doesn't mean I won't want to hire someone without side projects, but candidates having them 90% of the time are very strong.