The reason Chrome and Firefox are using high version numbers, and incrementing the Major Version number for each bug fix as opposed to the Minor Version is because they think the simpletons out there will assume:
"Well this has the highest version number, so it must have been around the longest, therefore it must be the most evolved and best..."
It's a ridiculous idea, that I'm sure some upper management meddler recommended to "out do the competition". Firefox should be no higher than 4.18 and Chrome being the youngest browser with the highest version number is just plain stupid...
Marketing = Deception = Lies... Just ask the masters of it over at Apple! Don't be fooled by these silly shenanigans...
Fast Forward to the year 2016 where we will have FireFox version 47.2 and Chrome version 62.1...
So annoying and stupid, sad thing is it WILL work on the simpletons...