Not exactly “defense”, but we saw something similar happening in the resent Armenia-Azerbaijan war. After they finally reached a ceasefire and many ethnic Armenians were forced to abandon their homes in the Nagorno-Karabakh region as a part of the peace deal. Many former residents burned their houses before they left. The reason they gave in interviews was they would rather see their house burned then to fathom the idea that their “enemies” would move into them.
Btw, a journalist who spoke to locals said some of the Armenians left the houses intact because they remembered moving into houses left from Azerbaijanis the last time around.
No, scorched earth policy is top down, systematic destruction of the strategic assets in an area to deny their use to an enemy, either to make the logistics of invasion more difficult (Russia during Napolean's winter expedy), to punish the inhabitants (Sherman's March during the US Civil War) or destroy the assets that made invasion worth it (burning oil fields, or Taiwan's bombs under TSMC).
This is just angry folks not want their family homes occupied by a national enemy. If we were seeing scorched earth, there'd be widespread destruction of roads, the power grid, any industrial facilities, and probably chemical posioning of any agricultural land
