there was enough abuse on both sides
One side commited much more of what you call "abuse" than the other. So much more,
in fact, that even comparing both "abuses" borders on indecency.
The link leads to an article about expulsions of Germans after WW2 - something that was
decided by the UK, US and USSR. Blaming Poland for that is somewhat strange, as we didn't
have anything to say (just as we didn't have anything to say about our post-war borders.)
Not that Poles were very eager to live alongside those who murdered them, but still - the
expulsions weren't our decision.
now, the WWII is over and it's time for forgiveness
Absolutely. I wholeheartedly agree with that.