There is no consensus to deprecate IEC prefixes

Twice now in the last week, a discussion that I started has been prematurely archived, without giving Headbomb a chance to answer the question I put to him. So let's forget the question and concentrate on the issue.

First, "What is an IEC prefix?" I hear you ask. Read this for a brief introduction and this for the case against the deprecation of their use on Wikipedia.

was there ever consensus on this?

There are several reasons to question that consensus was reached for the present deprecation of IEC prefixes:

the concerns of the 3 minority editors (in the 7-3 vote for the present wording) were not taken into account. All three (Seraphimblade, Thudnerbird2, Woodstone) expressed concerns about exactly the same piece of text in a larger guideline. The piece of text they were concerned about was the said deprecation. The reason for the concern, at least on my part, was that only 2 months previously, 11 editors had expressed a view that use of IEC prefixes should not be deprecated by MOSNUM (to none against).
I did not see a need to go over all of the reasons for an umpteenth time, as I could not believe anyone would have the temerity of ignoring such an overwhelming consensus against deprecation - I was wrong
despite this concern, the views of the editors involved in the 11-0 vote (against the present wording) were not sought
the discussion was held in an acrimonious atmosphere, in which any opposition to deprecation was met with a barrage of ridicule from Greg_L.[1] Some elected to stay away rather than participate in such a mockery of a debate.(under Evidence that editors stay away from MOSNUM due to disruptive behaviour); see also Omegatron's statement

is there consensus for it now?

Three attempts at starting a discussion were shouted down [2][3][4]
In the 3rd attempt, at least 5 editors (Jeh, Seraphimblade, Thunderbird2, Tom94022, Woodstone) argued against the present wording. Those who dared to support their view were met with further ridicule from Greg_L:

a similar number argued for keeping the present wording. They were cheered on by Greg_L
- Hallelujah, amen. Pass the collection plate and let’s get outa here.
the need to resort to these tactics to prevent even a discussion about the text demonstrates the weakness of the case for keeping it
the ridicule tactic is not new [5]

After those attacks I requested mediation. An offer of mediation was made by Doug and rejected by Greg_L.

And now, because I dare to question the claimed consensus, Greg_L portrays me as some kind of lunatic[6].

See also the theses of Quilbert and Omegatron on their personal spaces

The following WP Policy statements are relevant:

Reasonable consensus-building: Consensus can only work among reasonable editors who make a good faith effort to work together in a civil manner.
Forum shopping: It is very easy to create the appearance of a changing consensus simply by asking again and hoping that a different and more sympathetic group of people will discuss the issue. This, however, is a poor example of changing consensus, and is antithetical to the way that Wikipedia works. Wikipedia's decisions are not based on the number of people who showed up and voted a particular way on a particular day; they are based on a system of good reasons.

In other words, there is no reason to assign any more weight to the 7-3 vote than to the 11-0 vote before it. The dead horse that anti-IEC editors are so fond of quoting simply doesn't apply here, because there has never been a discussion that concluded in favour of deprecation that has not been dominated by abusive remarks from Greg_L. The result is that editors who wish to take part (like Omegatron and Quilbert) stay away from the discussion because they do not wish to be on the receiving end of such abuse.