I don't know much about the Kingdom of Jerusalem per se, but even today many Jews say prayers specifically written after the Crusades https://en.wikipedia.org/wiki/Rhineland_massacres So the symbols of "hope and triumph of establishing Christianity in the Holy Land" do not evoke particularly positive connotations, even aside from the usual modern opposition to that particular mission.

Hegseth thinks that.

The shooter who committed the 2019 New Zealand mosque massacre thought that.

Fellow members and leaders of Hegseth's National Guard unit thought that.

Crusader symbols in general have grown popular with many far-right nationalists, who see the imagery as a nod to an era of European Christian wars against Muslims and Jews.

Contemporary usage of symbols is often at odds with and regardless of any historic original back story and meaning.

Of possible interest: https://religionunplugged.com/news/pete-hegseth-trumps-defen...

and: https://www.thebulwark.com/p/pete-hegseth-christian-national...

Addendum:

> If Hegseth is actually proclaiming he's an extremist ...

Nope, he's always banging on about being a Proud, Patriotic, American, Christian, Nationalist. I can't say I've ever heard him proclaim himself to be an extremist ... save perhaps in the extreme love of God and America he professes to have. You can hear him Capitalise the words as he spits them forth.

Who on earth thinks the buddhist swastika is a German nationalist symbol? Oh, right, everyone who saw Nazis use it. Turns out that when one group uses a symbol to represent themselves, that symbol becomes associated with them. Go figure.

In this case it's not even "a symbol represents who it is used by". You literally linked to an article that espouses about how it's a symbol of the Crusades, i.e. united Christendom coming together to slaughter non-believers, in other words it has always been a symbol of hatred.