Don't think they disagreed with that part.
I think it's just recognizing the complexity of a world where even nazis will call their enemies "nazis" if it's useful to them.
The "if you are offended when I call you a nazi you are a nazi" is a weird take to begin with.
I think the comment you are replying to isn't arguing with the fuck nazis part, but the behaviour where progressive groups can be divided and conquered by socializing animosity between them.
Like when atheists were fighting against the heritage foundation, until they had to defend against claims of being bigots because "wanting to make circumcision generally illegal in the USA means you are pro FGM and you hate women, and if you argue otherwise it is an admission of guilt"
And all of the progressives were shamed out until the very groups that were actively fighting groups like the heritage foundation were terraformed into actual incel chud hangouts, while academic feminists were drowned out by the same culture war bullshit, helping to generally paint feminists as cringe karens, rather than a bastion against political movements by groups like the heritage foundation.
If you don't know why I keep talking about the heritage foundation, it's because they are the project 2025 people in no small part responsible for the current actual fascist push.
But.. That's difficult to explain while confronted by absolutist tribalism.
Don't be divided and conquered. It's harder for progressives to coordinate due to group complexity, but it's important not to do the work of the fascists for them.
Progressives fighting progressives because its socially expedient to not think about the bigger picture is indeed a big part of why trump is in power, which that comment seems to indicate as a bad thing.
That doesn't matter though if you just imagine their comment was "don't be mean to nazis!!"
If you just pretend they said that, it's so much easier to do the social peacock thing that has kneecapped progressive/leftist groups, and we can just ignore the failures of this behavior, because self reflection is bad for some reason.