My gut feeling (with bias) is that most people don't think about things around them because society is in a constant state of hurry. If someone is wondering 'how did zoning laws came to be?', they are not being productive. And our western society seems to value the individuals based on how much they produce.

The person working, or commuting to/from work, is tired and doesn't have the energy to ponder about the world around us.

The 'first researchers' if I may call them that, were the Ionians, a Greek island of merchants, that had the time and resources to pursue the interests of the mind.

That's of course, only part of the story. The other part, I'd say, is to have the habit of questioning and wondering about the world around us. That comes with practice. And ironically, lots of parents indirectly discourage their kids from asking questions by becoming annoyed at how many 'whys' their kids ask.

Our educational system is also discouraging of such way of thinking. It's mostly a production line of workers.