And why is it that bad? 1.0 is the final version, possibly with additional updates following which could also just be minor patches like bugfixes, so it is reserved until the game is done. Keep in mind that each number can stand for something different and does not necessarily follow the same rules, with the above as an example basically as a boolean "is it finished?".
Usually the second number refers to major updates and the third to smaller updates, and because of that they are not limited to just up to 9. Though there is also the possibility to do it like a percentage for completion, but in this case it does not apply.
But in the end it is the preference of the developer which defines what format they use, it could very well be an entirely different one or even a unique one.
