I could be mistaken but I think you'd only read bias like this on a United forum. Don't get me wrong, Vidic > Kompany is a perfectly valid claim but your points are skewed in favor of Vidic, quite a lot.
"Would stick his head in areas were others wouldn't put their boot" is not exactly a trait I would praise a defender with - same could be said about Phil Jones. Better fitness record, yes but Vidic was also injury prone and Kompany's real returning issues only started around 2014-2015 when he'd already been at City for a long time.
Also you're comparing players so no use to say "won more high profile matches for a team with far more prestige". You're also using that same argument as a slight on his leadership because he played in a lesser team which is crazy too. It's like using the argument that Kompany led his team in a World Cup QF win over Brasil in favor of Kompany, Vidic never even played in a World Cup (the most high profile matches of them all). Makes no sense at all. And Kompany by far edges Vidic on the ball regardless of whether Vidic is underrated or not in that department.
Again, perfectly valid to say that Vidic is a class above Kompany or similar claims, but the arguments you use are pretty weak and biased imo.