Sure, that we write "four-thousand three-hundred and twenty-one" as '4321' in stead of '1234' could be said to be "just convention". But your example is misleading -- it's too simple to illustrate the *real* problem. Decimal numbers are made up out of decimal digits; it's just a two-level hierarchy -- whereas in the machine-encoding of numbers we're discussing here, the basic binary-digits (bits) form bytes (eight bits), and the actual whole number is then in turn formed out of those. That's a *three*-level hierarchy.

In order to really see how stupid "little-endianism" is, you have to illustrate it with a similar three-level hierarchy. Here's one such attempt, using the popular "thousands-grouping" of binary digits: Consider the number "one-hundred-and-twenty-three-million four-hundred-and-fifty-six-thousand seven-hundred-and-eighty-nine" -- as a simple bunch of digits, it would be '123456789'; this is also *basically* the same as the "big-endian" way of writing it. The "little-endian" version, though, would NOT be '987654321'!

"Little-endianism" means ordering the BYTES "backwards" -- but the BITS within those bytes are still in the original order! The analogue in decimal numbers would be to write our numbers with the digits arranged into groups, like so: "One-hundred-and-twenty-three-million four-hundred-and-fifty-six-thousand seven-hundred-and-eighty-nine" = '123,456,789'. This is the "big-endian" way of writing it; larger-value groups ("bytes") come before smaller-value ones, and *within* each group, larger-value digits ("bits") also come before smaller-value ones.

The "little-endian" variant of the same thing is this: "One-hundred-and-twenty-three-million four-hundred-and-fifty-six-thousand seven-hundred-and-eighty-nine" = '789,456,123'! As you can see at a glance, digits ("bits") which differ in order of magnitude by only one step are far from each other (7 and 6, 4 and 3), while adjacent ones represent wildly different magnitudes (9 and 4, 6 and 1). It's illogical, unreasonable, and confusing... because it's bloody *inconsistent*!

Now, some "open-minded thinkers" among us may want to decry my complaint as a "hobgoblin of small minds", yadda yadda, cha-cha-cha... But at least in this case, that's bullshit. Consistency is what keeps us sane in a crazy world, what allows us to make sense of and cope with what we see, and (more directly related to the subject at hand) what helps us get the job done without going crazy ourselves; it is a "hobgoblin" only to those who have something against one or all of those.