I couldn't agree more. In fact I raised this question before the Hard Fork since it was the most relevant time to "warn" about it. But since I am usually not good in putting things into words, I gave up

I also don't see why the alert system is a point of centralization, or why they talk about risk of keys being compromised. A new alert system could have been put in place of the old like this:
The alert text tells the user that something is going on. Check where you downloaded this application for more information from the developers of the same app, and where would that be? Github, bitcoin.org, mailing list. But you at least told the users to go check it out and they won't be in the blind.
I don't see any way to compromise this either!

As for centralization, if you call that alert system centralization then you should call the fact that certain people are coding for bitcoin and @laanwj is the only person merging PRs (or possibly others) a point of centralization too! Because same people are putting up warnings on bitcoin.org, bitcointalk, reddit, mailing list,...

... BUT that is just what I think, and apparently nobody else agrees