Well I think that's the point - that everything is highlighted by the left, and Fuentes and his ilk are tired of them doing that, and just don't care. What's the harm in admiring Hitler if they already say you do?
Let's separate the rhetoric from the meaning.
In case one the rhetoric is, "Women have to be imprisoned," and the meaning is, "the hyper-feminization of our culture is a big problem." When Fuentes uses that sort of extreme rhetoric it becomes much harder to get people to hear an argument about hyper-feminization.
Or in your new case the rhetoric is, "Hitler is cool," and the meaning is, "Ethnic pride has a legitimate place, even among white people." Again, that rhetoric is going to be counterproductive. If Fuentes were not running around praising Hitler it would be much easier for conservatives to argue that ethnic pride is not necessarily bad.
Now on the other hand you are correct. Fuentes escalates his rhetoric because every time he speaks up about ethnic pride people call him "Hitler," so he just owns it (and this is very much a Gen Z thing). His escalation could be seen as a move towards factionalism and even violence (because when dialogue is abandoned violence tends to sprout), or perhaps it could be read as a good faith attempt to subvert taboos in order that the issues are no longer obscured. I would say that, at the very least, it is a risky move by a stark minority (i.e. people who are comfortable praising Hitler). That's why conservatives tend to distance themselves from Fuentes. He is a kind of loose cannon. His rhetoric stretches the Overton Window in a way that tends to harm the popularity of the cause.
At bottom it just strikes me as too cynical; too brash. A case in point would be his overt ridicule of Danny Finkelstein. Finkelstein deserved to be mildly rebuffed, but Fuentes' approach was far too crass and insensitive.
(At the same time, Fuentes is a very likable character. Those who go up against him tend to get the short end of the stick. I would be happy to have a beer with him and argue positions. Still, there is too much with which I disagree, both in form and in content.)