why recommend "portmaster -af" for full port rebuild?

[Andrew Hamilton-Wright]

Dear FreeBSD Docs,

On the upgrading/updating page:
    https://www.freebsd.org/doc/handbook/updating-upgrading-freebsdupdate.html
there is a line that recommends using
    portmaster -af
to rebuild all of the ports.  There is even a recommendation that '-G' be added to avoid interaction involving configuration screens.

This, however, ignores the many other interactions that portmaster still will require.

Is there no way to rebuild the ports without interaction?  It seems that even with
    portmaster -afG --no-confirm -y
I still get a long parade of interaction requests -- far more than I would if I used portupgrade.

I will note that Doug Barton, the author of portmaster, seems to advise against using it in this form, as noted in this thread:
    https://lists.freebsd.org/pipermail/freebsd-stable/2009-August/051623.html


Why is portmaster being recommended on this page, and if this is the best option, why is there no discussion of the many interactions that will be required (in spite of the implication of the discussion of the '-G' option)?

Thanks,
Andrew.