I think it's not a bad idea to overestimate the power of the government to track you; the common wisdom on the internet to make this assumption is probably a good thing so people are motivated to be as safe as possible.
On the other hand, it seems like the Tor users who get caught make clear, glaring mistakes in their opsec. And I always remember how long it took to catch the Unabomber, and how they apparently only managed to catch him because of his brother.