Shticky:
First, I’d like to see that source.
Second: I don’t think you should read that the way you are. It doesn’t mean that it is always inappropriate to exclude a group because of their beliefs. It just means that for groups which you are not otherwise mechuyav to hate, you should not allow your hashkafa disagreement to become hate as well.
As far as that goes, you have no reason to think that has happened here.
But also as far as that goes, I think we need to understand your source a bit more. We are mechuyav to hate tzedukim “??? ?????? ? ????”. So (if this source exists), it may be differentiating between hate based on the rishuus, and hate based on the personal things. So perhaps it is saying that the hate there became personal.