Saurus - Perhaps you believe that your comments were intended to be helpful and thus I will offer you the benefit of that doubt. I will address your mistakes in the order they appear.
First, even if "this forum is not frequented by the WP team" this does not exclude the possibility that one of them will have commented somewhere on a piece of their newest version which breaks functionality from the previous versions (and removes or obscures the old functionality).
Second, the WP site is filled to the brim with "official" instructions on many such problems. What I would expect to see here is merely a link to one such article which discusses this problem.
Third, and you should read this carefully, it is not a problem with a plug-in. The problem is with WP itself. WP has functionality built in which purports to upgrade any plug-in (through the WP site). However, all plug-ins fail. This is WP which is broken.
And finally, "Is there any reason on Earth you can't update like you did the others ... manually?" Yes, and I made this clear in the thread above also. WP is broken and needs fixing. Clicking the "upgrade automatically" will produce errors (such as put forward by FlashBuddy above). Clicking the "view..." link and then the "Install Update Now" link will produce the exact same results. In order to get the update it is necessary to click the "view..." link for that plug-in, then click the "WordPress.org Plugin Page", and then use that page to manually download the new version.
I'm just not sure how you thought you were being helpful.
All this being said, it appears to be a permissions issue of some sort. And yet there is no mention of the need to provide any special permissions to deal with the plug-in upgrades in any of the WP documentation, including especially the installation documentation.