Why do you say that? According to the Tor Project FAQ for their browser bundle, they leave JavaScript enabled. The only problem they mention is that selectively allowing scripts via NoScript permissions leaks information, so it's an all-or-nothing decision with regards to third-party scripts for any given site and they choose to make the default the one that breaks fewer sites. (And really, you're still free to block scripts from any third-party site that has an effective surrogate script bundled with NoScript.)