Meh, you probably deserved it.
I imagine the mod thought your post took a bigoted tone and he just slapped the ban hammer on you. And honestly, who can blame em'.
They more than likely don't want their forum looking like a Youtube comments section which can quickly happen since we've seen people who spam the word "PC" often don't appear to have any logic of what's out of line or not.
My advice if it wasn't a permaban is to just take it as a learning experience and make smarter post in the future. If it was a permaban, then just cut your losses and move on. It's not like you're not entitled to post there, and if they think they banning the worst faction of forum users and you get banned in the process, then so be it. It's best for both parties as you won't be able to post the content that you want and the staff would repeatedly have to take action against you, so either way, it's best to just cut ties now.
