Why do so much people hate on easy heroes?

Seems like a lot of people look down upon others who use the easier heroes. I've been seeing streamers and people here say things like Cloak mains in GM+ aren't "real" GM's, or MVP's don't count for Rocket players, or even Strategists in general aren't deserving of their rank, etc.

Why on earth would I purposely use a harder hero when I can chill as cloak and drop 50k heals + 12k dmg on your head? And why would that make me not a "real" GM? (Yes im salty lol).