Yes, the Unix world differentiates between point releases and major releases.
In the last decade, we've had, what, 7 OS X releases? All of which have had the same point release numbering system, and several of which have featured *exactly the same kind of problems as detailed in this article*.
What do we learn from this? That Apple's approach to version tracking is not quite the same as the Unix world's. Therefore, other assumptions from the Unix world (such as the impact of installing a point release) shouldn't be taken for granted when dealing with Apple products.
At some point, FruitMachine enthusiasts are going to have to accept that, marketing guff notwithstanding, installing a new release on launch date carries a non-trivial risk of something not working correctly. Just as would be the case with any other OS vendor.
Christ, I really don't see what's so hard about this. You'd swear it was some previously-unheard-of phenomenon rather than the same damn story we hear every feckin' time a new OS comes out on the market.