Why is the 3DS attach rate lower than DS to a significant degree? Did a lot of kids get Aqua Blues in 2011 with MK7 and then lose interest/get a smartphone? Are the core gamers buying 2 or more models just a larger slice of the sales pie this time given the system has declined significantly from its predecessor but are not necessarily buying any more software?
Where the heck does a system that sells maybe 60m when all is said and done even fit anyways? That's 20 behind even the PSP or the short-lived GBA. Moving to home console it's likewise for PS3 or Xbox 360. N64 is barely over half that at 33~ but I wouldn't call it a true sales failure, at least in North America where it wasn't too far behind SNES (but it did suffer a big decline in Japan and even Europe.)
Did 3DS outright fail or just disappoint?
It did prove that a low-res dedicated handheld could survive to some extent in a smartphone world with premium priced games, and not just in a handheld friendly market like Japan, it also dug deep for a market overseas, which wasn't easy. Can you call that an absolute failure even if it will never reach the PSP?
Considering the state of the market that the 3DS is in, I would say it is a success (especially in Japan). NDS is just on a whole other level and PSP AFAIK, got lots of its sales thanks to the rampant piracy to other countries. Also, software sales on 3DS is very healthy thanks to notable (MH) PSP franchises going to 3DS and new franchises (YW) with the continuation of some Nintendo games supporting the platform.
However, I see 3DS as a start of something not good happening for dedicated gaming. Mobile market had eaten significant portion of the portable market, most notably in the west, and this will continue to go on from now. NX will be the real test if handheld gaming could continue to strive. And although I would love a PSV, I highly doubt a successor for it would be feasible for Sony.
EDIT:
1. Why is the attach rate on 3DS worse than DS? Isn't the 3DS market slightly more "core" than DS at least.
2. Let's say 3DS reaches 60m units worldwide at the end of its run, no more. 60m is a big drop from 80m that even the PSP managed. Is 3DS an outright sales failure or just disappointing at 60?
1. It is because some games failed to have the similar sales it had on NDS (Brain Age, Nintendogs etc.) Mario, Pokemon and others had enjoyed similar success on 3DS despite lower install base and some third party titles such as MH, YW, P&DZ sold millions of copies.Core market is very much alive on 3DS.
2. It is a big drop but remember, as I said earlier, PSP number might be a little inflated due to piracy on the system. If we are comparing attach rate, I think it goes like NDS > 3DS >> PSP (more of a guess since I don't have enough reference on this). I think 3DS might sold more software than PSP despite lower install base, although I'm also not quite sure on this so someone may correct me.