Billboard Ads

Why do marketing people still insist on printing an ad for a roadway billboard in reverse? Way back in the dark ages it was an eye catcher, and it still is in a negative sort of way for me, and people would think 'boy that's clever' and go out and buy the car that's advertised. Nowadays it just irritates me. I think 'boy that's dumb' and don't even give the billboard a second thought. Except to stew over some marketing guru's brain fart.