First, this is one of my favorite game, so your assumption of bashing this game its purely in your brain, it can be put where I think.
Secondly, I have downloaded over 10 recent updates and, based on my experience with this game, each update has been +0.1.
Therefore, if it continues at this rate, we may expect to see the complete game by 2028.
He's right about your understanding of versioning numbers.
The current
major release is 0.52. The version is 0.52.1, since the .1 is an update of 0.52 that includes bugfixes.
IF this game goes on for another 48 releases (not including bugfixes) then you're correct about how long, but not why. For all you or any of us know, there may only be another 8 or 15 releases until the game is done, which would make it version "1.0" or "1.023.987c"
At the same time, there could easily be 96 more releases, and then it could be 0.148.01. It could just as easily be 0.1.48 or 1.48 too, since there's no universal standard of versioning systems.
Hell, it could even just end at version 0.55.1 because the dev decides that's where it ends. At that point it'll either be "0.55.1" or "1.0"/"1.01" etc.