It's easier to understand if your diagram show the starting memory positions (address 0x00000000) at the top, and final positions (address 0xFFFFFFFF) at the bottom. This way the top of the stack is, precisely, at the top.
It doesn't seem to be an standard and there are almost the same number of diagrams with memory from 0 to F than from F to 0. Some of them are more useful in specific contexts, but most are simply drawn the way the author is used to.
Personally I prefer increasing numbers go down, like lines in a file, numbers on a numbered list, timestamp on a log, etc. Having the highest memory value 0xFF on the top seems...odd.
It doesn't seem to be an standard and there are almost the same number of diagrams with memory from 0 to F than from F to 0. Some of them are more useful in specific contexts, but most are simply drawn the way the author is used to.
Personally I prefer increasing numbers go down, like lines in a file, numbers on a numbered list, timestamp on a log, etc. Having the highest memory value 0xFF on the top seems...odd.