Why is LTC not popular?

The power useage is what protects bitcoin. The more hash power costs the more difficult to attain 51% hashpower to control the network. Power consumption is a feature not a bug. Besides lots of bitcoin is using isolated energy sources that would not be consumed generally. Such as isolated natural gas that would be flared off during oil drilling. Isolated geothermal pockets, etc. The cost of mining protects the network just as building an expensive vault protects the gold that’s in it.
Or the cost of military to protect a fiat currency useage ( US dollar ).