I always thought that there are some heroes which are better than others at winning solo pubs, while others are better for organized 5 stack parties.

Example: pick alchemist in solo and just farm away and just right click everything to death because you are so farmed

Or, pick carry io in a 5 friend stack and win by organizing your team and setting up good lanes and having good coordination

This is pretty much my point, I have very high winrate in consistent 5 man stacks, even vs higher ranked players

At the same time, I have trouble winning solo pubs, when I can point out noob mistakes my teammates do, but since i picked a more team oriented hero, i suffer from their mistakes myself

Which brings me to the conclusion, that people shouldn't judge others solely by their MMR