In too many games I've seen duelist players force armour+sheriff after losing pistol round, or not saving on the bonus round. This severely decreases the chance of winning the game due to the team's overall buy being 1 person weaker than it...

What is the reason that makes some matches end up one sided, even in pro gameplay i see that happen sometimes. I am pretty sure it is not(but maybe sometimes in solo q or comp in general) because of mechanics. But what is the reason behind...