There are two main factors (besides the obvious lack of free time) that keep me from posting more frequently to my blogs. The first is a fear of mistakes. I fear saying something dumb, whether it is just a simple typo or if it is not thinking through my ideas enough before committing them to the Internet. The second is that it is all for naught because no one reads what I write anyway. However, if I want readers I have to post regularly, and if I want to get better at writing, I have to keep doing it. So, for me, a large part of writing posts is a psychological battle with myself.
When writing software, there are also motivation issues that prevent or slow down development. I think one of the key reasons Agile has such vocal followers is that it addresses the psychology of programming, keeping developers happy and productive.
Fear of Mistakes
While Agile may not explicitly say "Embrace Your Mistakes", the idea of constantly refactoring along with a large suite of automated tests and continuous integration attempts to address this fear.
Useful Software
The other day I was reading a friend's blog (May Contain Blueberries) and he mentioned that he read and enjoyed my blog. This gave me a huge emotional boost, which encourages me to keep writing. Similarly, besides all of the tangible benefits to quality that a release early and release often philosophy that Agile has, there is the huge psychological benefit to the development team having people use their software. Nobody wants to work on something that never sees the light of day.
Staying Productive
Other ideas that Agile methodologies tend to push are Pair Programming and No Overtime. The No Overtime philosophy is explicitly about programmer morale and mentality and keeping them sharp. Pair Programming also has this affect. When pair programming, you are less likely to be distracted by emails about lolcats. You also have a compatriot who is in the same boat as you, sharing your miseries and successes.
Developers are People
Basically it comes down to the fact that developers are people. Keeping us happy and motivated is a key component to continually getting quality software over time. And, while free snacks are a tangible way of accomplishing this (and let me tell you, the Google snack rooms are pretty awesome), process and business practices are more important over the long haul.
As a postscript - it seems that I must feel strongly about this. I just noticed that I had already posted on Psychology of Extreme Programming. Oh well. If its worth saying once, its worth saying twice. :) Hopefully I made enough new points to make it worthwhile.