Achievements/Trophies are a very interesting part of the metagame and they need to be handled correctly. A set sort of standard certainly helps, but there needs to be a draw for them to be successful.
Anecdotal evidence but humor me. My brother in law had a original 360 (until the disc drive broke no rrod) and he just played games, had literally no interest in achievement hunting. Instead of replacing/fixing the 360 he got a PS3 (friends were on it) and suddenly what games that had trophies he wanted to collect trophies in. Whatever weird psychological differences between the two, one mattered more. I suspect the lack of an arbitrary number score and the change to the metal type of the medal to be the factor.
Nintendo can't just add them and go, "hey we have this now" the way Steam did. There needs to be actual thought into it.