jQuery sets itself apart by focusing heavily on DOM manipulation and traversal. Because it's central core is based around getting elements and doing things with them (show, hide, fadeIn, fadeOut, load contents from Ajax, etc.), virtually all plugins integrate into the library as though they were part of the core.
For instance, in jQuery you can do: $("div.hidden-contents").addClass("shown").fadeIn("slow").load("some_url_for_ajax").
If you loaded in a (hypothetical) tree plugin, you could do:
Well then, it isn't jQuery syntax you're having an issue with. That's sort of like saying, I don't like the java.util.text package because I don't like Java.
Seriously, I think that when people first see jQuery code, it's the $ that throws them if they haven't see it used as an identifier before, and perhaps the syntax of the more advanced selectors (which people love to throw around as examples).