When regarding the three console makers, it's helpful to remember the role National Identity and Cultural Psyche likely plays.
Microsoft, fundamentally, is an American company. Sony, while originating in Japan, is an International company - which at this point basically means an American-style company that keeps a Pocket Guide to Local Ettiquette when it travels. And you can see that in their very American (or "Western," if you prefer) approach to tech and innovation: Risk/Reward as balanced-scales, aesthetic is consumer-maleable, "good enough" is sometimes acceptable (re: "we'll patch it down the road") if timing is a factor, etc.
The whole concept of Achievements, likewise, is thoroughly Western; and not only because Western gamers are more enamored of online gaming than their Japanese counterparts. The basic appeal of XBL-style Achievements is rooted in the sense that accomplishment only "counts" (or "counts MORE") if it's expressed as a quantifiable "thing" that you can show-off to others - and that sense is "native" to a Western/American sensibility.
Nintendo, while they might be technically "international," are fundamentally a Japanese company - NOA and NOE aren't part of the "brain," NOJ is the brain and the other branches are "hands." The Japanese "psyche" is on a different wavelength than the Western, and you can see it in the way Nintendo approaches it's products: Repetition-as-the-key-to-perfection, in a nutshell. You're never "finished" getting good at something, so do it over and over to the point of zen-like "fusion" between creator and act of creation. The trade-off is pretty steep: "Innovate" becomes a four-letter-word, but the payoff can be extraordinary: "Mario Galaxy 2" is as close to perfect as any game you'll ever see... and why wouldn't it be? They've been making it for 25 YEARS - They are really, REALLY good at it by now. Not judging either philosophy, just pointing out: They're different.
By the same token, Achievements as we know them from PSN/XBL are almost totally antithetical to the (traditional) Japanese psyche: "Replay value" means playing the game again and again until it's practically a reflex. Accomplishment is for personal contentment and growth, not something you want quantified for "bragging" rights - "bragging" itself is a social faux-pax for the most part in that culture. And while said culture may be changing on the "ground level" in those regards, you're not going to see a century-old company acknowledge or embrace it other than in increments so tiny that the change is as unnoticed and "painless" as possible. And make no mistake: Nintendo is superficially about "innovation" and wacky experimentation, especially at Western press events, but the above-described is pretty-much how they roll.
