Ok, look, here is the deal.
Sometimes, I manage a customers website. When I am the one doing it, I do all the updates, since my customer NEVER looks at the back end.
However, there are customers who like to think they are saavy and they are not. I build them a site they want with a custom design and get it running, get their content posted and then hand it off to them. They are well informed of the fact they are on an open source platform that gets upgraded often... along with plug ins that also get upgraded often.
That doesn't change the fact that these 'saavy users' will send me an email that says "I've had to upgrade this code 4 times plus upgrade the XX number of plugins... why the hell do I have to keep doing this?"
That's not *me* talking, that's an end user.
For the clients I have that do have these complaints, I will be adding the plugins suggested and I will manage their sites on the backend of my dedicated server.
Regression cycles, QA cycles and release schedules are all dictated by development and marketing. Neither one leaves the appropriate amount of time for QA, ever. The whole idea of agile or scrum engineering makes me want to barf, since it's always about getting code out fast. The problem with that is you leave yourself at risk for missing testing in the regression cycles, like the permalinks problem a few rleases ago... a simple feature that went belly up and it never should have.
I've done my share of QA work and set process in place for many startups. Every one will say "go fast" and every one winds up having to "slow down" because go fast = breaks eventually.
If it were mine to do, I'd remove the 'visible' upgrade notifications and put something on the dashboard that allows you to see the release history and the issues fixed by it.
The X.X.XX version is available, please upgrade now is cryptic at best. Same goes for plugins.
If a user can see a list of fixes and dependencies, they can then choose whether they are affected by those changes and make a decision as to if they should upgrade or not.
Updates where interfaces and functionality changes are implemented should be considered 'upgrades', they are new releases... and given the speed with which the fixes come ofter point releases and then the flood of plugin changes, many of us choose to not move right away, just to avoid more work just get get the current content and functionlaity working.