Just because I am a “computer guy” at work, I don’t necessarily know how to make your exact model of printer print. I don’t necessarily know how to set up your exact model of wireless router. And I definitely cannot make your grandma’s PC running Windows ME run much faster (at least I don’t want to).
I am a software guy. I am not an expert in hardware, and even if I was, I would probably not know about your consumer goods that you bought at Best Buy.
Don’t get me wrong, being a geek, a fairly logical guy and a good trouble-shooter, I probably have a better chance of figuring out your problem than 85% of the population. And don’t get me wrong, I don’t mind helping out immediate family and friends when trouble comes knocking for them. But I am not willing to help a human resources co-worker’s uncle’s friend’s sister’s boyfriend figure out how to network his printer.