The answer is simple. Because in Europe are Germans and Russians and most of time they spent attacking other people and trying to steal their land.
You and Germans. Will it ever work out ? We have forgiven them . It was hard, especially when we lost the world cup finals against them in 74 (eventhough I was born 19 years later, I get reminded on it every World or EU cup).
Ahem... May I present to you the battle of verdun, a battle where nearly 700.000 men were killed. That is almost 50 times more than the battle of kleidon and I'm very sure that a lot more than 15000 were blinded.
Now let us compare the population of the middle ages, and the modern time.