Why all mechanical keyboards needs to have those weird RGB lights? I understand that it might be useful to have backlighting, but why it's always RGB? And befor

Why all mechanical keyboards needs to have those weird RGB lights? I understand that it might be useful to have backlighting, but why it's always RGB? And before anybody will tell me - you can turn it off - yes, I know, but why it's there in the first place? I know that gamers like to have those shiny lights because these are additional points for their skill, but I'm not a gamer.