Because we aren't simgods that know the origin of each and every sim racing content. We comply with our terms and rules and if the original owner of this track has a problem with it they can notify us and it will be removed on the fly http://www.racedepartment.com/forum/pages/terms-of-service/
I don't know much about Simraceway's content to be honest but I am sure if this really comes from the sim, the uploader of this track can prepare himself for some upcoming troubles as thats a full breach of both our as the SRW ToS and EULA.
At some point the luck of some of these modders will run out.
If this does end up getting removed, then the Lime Rock should go as well....seeing as it's also a SRW conversion....