Is the wording incorrect or ambiguous?

I'd say ambiguous. Somewhat a desire to dodge responsibility perhaps, but that's also somewhat fair because as I stated earlier, the true decision makers are the stakeholders via witnesses as I will describe again below.

Or did Steemit Inc decide off their own bat where the ten percent is coming from? It reads as if the witnesses proposed it. Which is the basis of my original point.

They asked for input and witnesses gave their views. The way the process works is:

1. Discussion between witnesses and developers (Steemit in this case). This discussion is advisory and can not truly commit to anything because the witness list may change (see #3 below). The discussion also goes in two directions: a) witnesses indicate what they believe is best for Steem and what stakeholders want, b) developers indicate what they believe is best for Steem and what they are willing and able to develop (as well as covering schedules, milestones, roadmap, etc.)
2. Developers (Steemit in this case) release code implementing a fork. This has not quite happened yet, but there is a release candidate or near-candidate under final testing.
3. Witnesses decide whether to approve/activate the fork implemented by the release. Stakeholders can change witness votes to influence the process. The witnesses voted in when the fork needs to be approved are not and will not necessarily be the same ones that were participating in discussion in #1 above.
4. If approval does not occur in a reasonable amount of time, either return to #1 or #2 and repeat, or drop the effort to make changes at this time and the blockchain continues to function as before.

It is also worth noting that the process has a relatively high hurdle in terms of voting to make a change. At least 17 of the top 20 witnesses (which are voted in at the time of a fork, not necessarily the same ones as now) need to approve the fork. So stakeholders who want to stop a fork need only replace 3 or 4 witnesses (I don't recall which) with new ones who agree.

I certainly don't mean you when I say the average user has been ignored and maligned

Well who then?

authors have been blamed for selling and putting downward pressure on the steem price

I don't consider this maligning. It may be a true statement about the economics and market. This does not mean that any individual author is doing anything wrong, or even that all are. But this is may be more about how efficiently rewards are used to create value than the fact of them being paid at all. That doesn't make the problem go away though, and authors as much as anyone suffer from it (lower price -> lower rewards).

IMO people working on EIP, SPS, witnesses, and developers are all making a sincere efforts to improve Steem. If you think anyone is acting against the best interests of Steem overall you are entitled that view and IMO should absolutely call it out. I don't buy the view that adjusting rewards and mechanisms, even in a way that may (though I remain unconvinced) be negative for authors, is bad for Steem. Steem is more than just authors, but authors are surely part of Steem and worthy of respect, just not absolute deference to maximizing direct author rewards to the point of failing to make Steem the best it can be.