I'm not sure this is really a bias. Maybe it's just that the cost of acquiring propositional knowledge has decreased more relative to the cost of acquiring procedural knowledge, in which case it's quite rational to accumulate more propositional knowledge. Emile made a similar point.

Also, I have an anecdotal example of propositional knowledge clearly beating procedural knowledge. I used to have shoulder pain from using computers too much. I visited a doctor and a physical therapist, and neither of them were able to help me. I ended up solving the problem myself after reading books about anatomy and physiology, and then doing Internet searches, which found a crucial piece of propositional knowledge that the doctor and therapist apparently weren't aware of.

About your digression, personally I've found that most of the propositional knowledge I've learned for fun has ended up being useful. Maybe that's just a coincidence, but there are also things I think would be useful for me to learn that aren't fun for me, so I think it's probably just that the value of propositional knowledge is pretty high in general.

BTW, if you have a lot more knowledge about programming than you need for your current work, why not look for a more challenging job or project?