it has nothing to see with videogames, most published videogames never showed black bars.
Yes, because they are using scaling to compensate that. In 3d games they usually change FOV of the camera to keep gameplay the same. In 2d games is almost the same but instead of changing FOV (there are no 3d cameras to do that) it's made by simple scaling. In both cases player is in the same spot on the screen but environment is scaled to see more or less respectively.
Try playing for example some fps shooters on computer monitor on different resolutions and on tv (4:3 and 16:9) - do You see any stretching?
and you keep mentioning games that uses stretching, can You provide some example of that games?
No one here is trying to be insulting, disrespectful or what ever. We just want to say that this is not the professional approach to design games and should be avoided at all cost.