Just because Mozilla has their reason for making the change doesn't mean everyone has to be happy about the change. I'm not complaining about Firefox, I'm complaining about the number, and the corruption of what that number is supposed to mean.
Don't be. There will be no "major additions" anymore. They will now release small features, quickly. So no major feature bump. Hence no need to wait for one either. It's like a number of small steps instead of one giant leap.
I agree that it's a redefinition of what "version number" means: now it's essentially date based, rather than feature based (though the two are obviously correlated). But I can't see any obvious reason to read "redefinition" as "corruption". It's just different, and both Mozilla and Google had sensible reasons for making that change.
In fact, their decisions may make it worth questioning those assumptions more broadly. Is there a chance that your version numbering method is causing subtle problems for your own development process?
This rapid release schedule is just the most efficient way for these teams to deliver new features in a stable way. Taking 1-2 years to land code in the next major, stable version of the product just isn't practical anymore.
People get way too hung up on the actual number.