I just see organization as the most efficient way to reach my goals. It helps me stay on track and directed. Though I don't really see myself as intensely organized as some people. I just don't have the patience or energy to be one of those OCD organized people. I just maintain a level of structure to keep things flowing, but within my own personal limitations and desires.
I like to organize and structure when I know that I'm going to see a direct impact from it. I got obsessed with reorganizing and restocking things at my job because I knew that I'd see differences in sales from the difference I made. My Te isn't directed toward viewing personal organization as a necessity. It's directed toward analysis, efficiency and productivity. Personal organization is just part of the equation.
A lot of it comes from a desire for control. That's Te again. If something is messy, I reorganize it to regain control of the situation, not just for the sake of organization or to make it look pretty. A desire to plan comes from a need for stability, predictability and productivity. I won't do something that I don't view as productive unless I have a personal reason otherwise. However, we all have our own view of productivity, so this leads to a lot of people misinterpreting ISTJ's not wanting to "have fun."