I'm not convinced they're as much jokes as real concerns by people who have already been burned by this (see: YouTube -- I'm not going to argue about whether or not G+ integration has made these products better, but it's not unreasonable to not want your real-name associated with comments you made under a pseudonym, and to be so annoyingly pestered to do so!)
Google+ is Google's social layer. Commenting is an inherently social activity and it makes sense to have a common layer i.e. G+ here to handle them. Changing the temperature is not a social activity.
So no the jokes are not real concerns and are mostly silly intellectually lazy exaggerations.
