Yes, that's a good example of anachronism, I think. You can't ask for evidence for a very famous Jesus, if he wasn't very famous then. If he had been, it would presumably be legitimate to ask for more contemporary accounts, by other Jews or by Roman writers.
One of the problems here, which crops up a lot, is the Christian veneer which has been placed on these narratives. I mean, some Christians don't want to say that Jesus was an obscure Jewish preacher, they want to say that he was from the beginning a shining and obvious theophany, or whatever the right word is. If he was that, we would expect more reports of him.
So because Christians have given this kind of back-editing to the life of Jesus, it is tempting to follow suit. However the Christian theophanous Jesus may not be the historic one, who may be a Jewish (obscure) Jesus! So there is a kind of deChristianization at work in this process.