Why is my Walmart more protected than my kid's preschool?

Walmart has the lowest prices in town on a lot of items.  This is probably because they're often the only store in some towns.  Recently, I took my son to my local Walmart and began to notice the amount of exterior cameras that were there.  I counted 45!  Then, I began to think of how many must be inside and I remembered seeing they had a roving vehicle patrol contracted to a major security company.  That's when it hit how serious these guys are about their stuff during holiday shopping season or any season for that matter.  Geezo.