It depends really. Everyone nicks mods/code bits from other sites. If they copied the style completely, yeah, that's crap, but there really isn't much to be done about it.

Not to mention that this style is a beast. I did my own version of Princeton's tab script up top. It took me months to sort out and doesn't work/look nearly as good as his does, but it's where I got the idea. I honestly can't see many people being able to spot-on copy this theme without being good enough to code one like it of their own.