The 'Lighter' Side Of The Force
Dont care. Doesn't matter. Not important. Poster is an idiot.
We have to first point out the obvious. Lucas was making this up as he went. At first Vader wasn't Luke's dad and Leia being his sister was added to wrap up the story after George had fallen out of love with making Star Wars films after the break up if his marriage to Marcia. That all said it's still a weak theory to justify the bad writing of the prequels. But it fits the shifty retconman Kenobi to put Luke in danger like that but Vader hates sand so maybe that's all the protection he needs. Maybe Shmi's ghost protected the farm from Vader?