Except that it is. You don't dissuade a racist or a misogynist or whatever with brain surgery. You just show them that their model of minorities/women/homosexuals/whatever is flawed. You don't alter their brain to terminally value, say, preventing slavery, you just show them that to satisfy their existing terminal value of avoiding human suffering they should prevent slavery. That has no effect on Coherent Extrapolated Volition.
Except that it does, because having been persuaded they extrapolate differently. But maybe by CEV you mean some idealised version.
Your impression that it is obvious that changes in de facto ethics are not changes in basic values rests heavilty on the assumption than basic values are in hardware, not software. That is not obvious , either.
Here's the new thread for posting quotes, with the usual rules: