No, you just don't understand. It is perfectly acceptable to say that subjectively all knowledge is subjective. You're just dismissing the possibility because you don't like it. I am using logic to address it. Logic is not subjective.
Subjectivity is relativism.
The problem is that it is self defeating. I'm not saying that some forms of knowledge cannot be subjective. I am saying that there ARE logical absolutes. That is the issue. Here is the point.