From my prospective the primary reason for this, is because people in general are ignorant how a fiat system works and have no interest in educating themselves.

For people who understand how the fiat system works, I'd guess they already have a small bag of BTC.

My small bag is providing me with an ROI of 400%. It is a store of value for me.

As for Lightning and ecash it is predominately all beta software currently, so it needs time to mature.