Re: NASA use Macs?
I have to assume that you work at NASA, going by the authorative nature of this comment. Although the overall feeling I am left with is that you are guessing (my opinion obviously).
If you are doing number crunching on a computer then you need to know how the hardware, OS and complier handle data types such as integers and floats. This information is widely available irrespective of the open/closed status of the OS. Also, remember that one of the most powerful computers on the planet is a cluster of Macs.
If you want a super reliable system then you are going to base it on an RTOS such as LynxOS. Something where you know what is going to happen and when. The RTOS example given is open standard but closed source so, by your argument, not suitable for safety critical applications – exactly the market in which it is promoted.
"there's really no practical reason to use MacOS at the end of the day because it doesn't do anything practical that other OS' don't do better, aesthetics do not make up for lack of practicality at the end of the day."
This is just rubbish. Are you saying that OS X (not MacOS – different thing, think of a number 9 or less) is “worse than every other OS out there for everything” or that “while better than some at some things is worse at others”. The first being untrue and the second being irrelevant until a set of requirements are compared against performance. There is always a practical reason to use any mainstream OS. If there wasn’t then it would disappear, as many have.