Any Real Programmer knows that 0100 is ADD, that 0001 is "perform this instruction if the Zero flag is clear", the numbers of the registers involved, etc. The right bit masks to combine such simple concepts and a reference to remind you of the bit patterns for all those extraneous instructions like SADDSUBX is all you need. ;-)

That's relevant to ARM, BTW. Some inferior Johnny-come-lately platforms probably used the wrong values. They might even involve microcode, the losers. ;-)

Tradition, nostalgia, popularity, trendiness, neophilia, neophobia, and familiarity are all powerful forces. We happen to be in an industry in which all of them compress into decades rather than millennia. Sometimes that's fortunate and sometimes it's unfortunate. What really matters most is what works, but we'll probably never overcome the "cool" factor. It's even fashionable to not care about trends.

What we should really try to figure out is why the first movers before a trend move to something and why the last movers abandon it after it's unfashionable. Once trend following, neophilia, neophobia, xenophobia, xenophilia, and every other secondary, tertiary, or downright meaningless motivation is eliminated we can see the true value of what a system's designer got right and what was broken.