This isn't a game where you are beaten solely by 1 Factor
So stop bitching about Vayne, and stop bitching about niche champions like Yasuo and Riven who need very exact circumstances to defeat their opponents. This is a MOBA, where the difference between life and death is made in split second decisions. So much goes into a loss or a win such as team composition, TEAM WORK, awareness of what's happening on the map, skill level of your team vs the skill level of the enemy team.
killed my whole team?"
HOW!? Yeah I agree.