Plus if we get to raze Orgrimmar to the ground, so be it!

The Orcs are due y'know from their little Stormwind vacation in the First War.

The Orcs are not "due" they paid for their "vacation in Stormwind" with years of enslavement...

Years of enslavement is nothing compared to total genocide. So no, they haven't paid.

To be fair, it was only partial genocide ;)

And we only killed the ugly humans ;)

I hate to paraphrase Garrosh to make a point, but:

Why should the new generations pay for the sins of their fathers?

We don't punish present-day germans for the crimes of the nazis.

It's not like the orcs that were fighting in the first and second war are long dead and the orcs living now are their great-great-great-grandsons. It's only been around 20 years since the end of the second war and many of the orcs who fought back then are still fighting right now. Sure, there's also a younger generation, but even that generation were mostly kids back then and they all saw their parents killing and murdering. Few adult orcs were born after the second war.