But if I told you to "hodl" a stock or house or anything else really you'd think I'm crazy.

Nope, I would tell you that you were exactly right, that's where the idea of HODL comes from. Warren Buffet advises you to buy a stock and keep it forever when possible. They are not really making more real estate. The only reason to sell a good investment property would be if you are retiring or something and ready to cash out or to buy another property.