We block accounts and IPs that are unable or are
unwilling to control
themselves and behave in a productive manner.
If someone is enough of a harm to justify a technical block from "X"
then they really should be blocked completely. We are not so short on
people that we should be accepting harmful folks and trying to limit
them technically to the spaces where they will only do the least harm.
... Harmful users should be blocked.
We enforce bans with blocks, why not enforce topic bans with topic
blocks? Also, our advice regarding conflicts of interest is to edit
the talk page instead, why not enforce that with code?
I might take a look at the relevant parts of the code and see if I can
implement something along those lines.