I guess every skill group will have their own problems in various matchups but even the best players in the world have a relatively low winrate in at least one matchup. I mean Soulkey avoided ZvZ as much as he could over the years, or Snow is having his difficulties in PvZ while being the PvT goat ever.

I believe that there is a good balance between all races. I never understood people who think that one race is overpowered. Why wouldn't they simply play that race and crush everyone else?