If you have discussed those things previously with the poster, I don't agree. If you were to go digging through their history only to respond to the current comment, that's more debatable. But, we're supposed to assume good faith here on HN, so I would take the first explanation.
In this case the poster seems to have projected opinions on to a post where none were expressed. That seems problematic regardless of how they came to associate the opinions with their respondent. Maybe the poster they responded to still hold the projected opinions, perhaps that poster abandoned the projected opinions, or perhaps they thought the projected opinions distracting and resultantly chose not to share.
If I am wrong or not useful in my posts, I would hope to be allowed to remove what was wrong and/or not useful without losing my standing to share the accurate, useful things. Anything else seems like residual punishment outside the appropriate context.
When I see a post I strongly disagree with, I tend to check out the poster's history: it's often quite illuminating to be confronted with completely different viewpoints, and also realize I agree to other posts of the same person.
