Movie question

In movies, especially boomer ones, why do cowboys or the heroes of the movies shoot a villain, then gently push their foot on the body? I guess you could call it a "kick" in the loosest of language.

What's the point? Some movies even subvert this where the democrat in The Hills Have Eyes does the same thing, but the dude is still alive. Once democrat turns his back, dead guy picks up his gun and gets ready to shoot him with his shotgun.

Is this a case of liberals being liberals? Similar to why Star Trek does that **** of interlocking your fingers to punch people? Even Bond is guilty of that too.