I wouldn't use the word "heritage" because that sounds like a fallacious appeal to tradition, but Unix is definitely a culture and it can be useful to think in those terms. (Check out http://www.faqs.org/docs/artu/philosophychapter.html if you haven't already.)
There are now several projects that are using Linux but aren't really part of Unix culture (OLPC, Android, Ubuntu, to a lesser extent Fedora with all its Lennartisms). I think it's arrogant to assume that Unix has already gotten everything right so I support all this exploration, but perhaps it deserves a warning label like "Fedora's not Linux as you know it; Slackware is that way".