Just note that for the purposes of this discussion, there is no evidence of this whatsoever. Julia is used by an ever widening audience, but even if it wasn’t, the causal connection to scoping rules (which are pretty arcane for most people) would need to be demonstrated.
It will be possible to argue about these things constructively at the appropriate time (in preparation for 2.0). There is little reason to invoke the “Julia is doomed unless …” line of arguments in the meantime.
You can find out the history with a trivial investment into researching the issue, eg here I collected some starting points. Just keep in mind that the issue is really complex, and the design space for scoping rules is full of trade-offs with a lot of use cases to cover, so it was a long process with a lot of discussion. IMO the manual may not be the right place for the history of scoping in Julia — it should just document the language as is.
That said, if you find the manual unclear, please consider making a PR. New users are in the unique position to do this, because they still remember the difficulties they encountered.