I think this should not be allowed either because it is plagiarism, the intended use is irrelevant.
What made you change your mind?
Unless you think that Vadi2323 is actually promoting terrorism, this is either parody (may be fair use) or satire (probably not fair use). Given that Vadi2323 seems to be ridiculing the Chipmixer campaign itself - it could be considered parody. On the other hand, he could be targeting privacy/anonymization in general, in which case it's more of a satire. IANAL.
This.
Good quote. I am not sure that my previous agreement with this stance was the right decision. There can be so many edge-cases because of that. I think it would be much simpler if we uniformly disallow any kind of plagiarism/copying and modifying. If somebody wants to make a parody, then let them make their own design(?). What do you think?