No, it's absolutely about the common ground. The arguments themselves that are being made. All you are saying is that unless and until a "heritage American tracing roots to the colonies" comes out saying what Nick does, amassing the following Nick has - that until then we should have no structure, leadership, or organized political goal. And that is ridiculous because of what's at stake, and exactly why the purity spiraling is so toxic to these movements.
It has been discussed in this space that perhaps Whites have too much baggage, regardless of what you want to consider White. You're standing in the way of unifying a political project because of phenotypical traits so redundant you have to spice them up with ad hominems to attract attention.
You say Nick is injecting himself where he's unsuited, or that leadership "belongs to those with an actual genetic and cultural continuity", but these are part of JF's point. Out of all of your assumed percentage of Americans that could fit this description, there is no one even close to making the cultural impact of Nick Fuentes. Not even the biggest fan of Nick, although he's certainly better than the vast majority; but to hitch your wagon for a political project on pretending like the genetics of "Northwest European stock" is so easily traced and unblemished - even by 2 centuries of European mixing - is *ridiculous.* And, most importantly, subjective.
I see the common ground as being worthy of allying with many facets of the space, least concerning of all the trifling swarthiness of an otherwise politically effective, and White-identifying, personality in Nick Fuentes. You have no choice but to face the reality of your situation: Nick is an avatar for the intersection of what Whites are thinking but are still to this day too afraid to say.