Why does Mayweather have to photoshop himself into other fighters' moments?

Why does Mayweather photoshop himself into other fighters' moments. Like Marquez & Garcia knocking out their opponents. The same thing goes for people who do that sh*t on here, too. What's the deal with that? Why doesn't Mayweather actually fight Pacquiao, Maidana, or Khan instead of pretending to knock them out through the power of photoshop? Why does he have to pretend to beat them, or only imaginably beat them. The same thing goes for people who do that stuff on here. That's weird stuff. Why do you guys have to photoshop your fighter into a situation they were never in? That's like some straight up fantasy stuff going on right there.