Because people are idiots.

It's called EyeTOY. Sony fans don't play with TOYS, they are hardcore/extreme/badass/gangsta. Yeah, I know it sound strange, but I knew Sony fans that told that to me "it's a toy".

 Sad but true...

I think it's partly due to the way Sony thinks about the product. If they had intended on revolutionizing the way we play games, they would have marketed it differently, and made sure that there were better games for it. This way it could have become an extreme hit, providing that the general image of the PS2 would not have gotten in the way.

It's the company's attitude towards these things that is the first and foremost reason that Nintendo is selling millions and Sony is not (not that they weren't/aren't, I just don't know how to say it differently).

EDIT: Basically, what I'm saying is that if Nintendo had made the wiimote a peripheral and tossed it in with a couple of lousy games, they would most definatly be last this generation.

 simple, no bundling from launch with free game, lack of games for it and nowhere near the amount of media coverage.

QFT. 

EyeToy and PSEye are also too limited for anything beyond specifically designed games for it.  The Wii-mote is the same to an extent but is far easier to incorporate into games than would be either camera peripheral.

 Devs still can add in bonus features if you have it. Look at what EA did with Burnout. It supports the PSEye. Also wtf are you talking about them being limited? The PS3 has added in more functionality with the video chat feature. Plus EyeCreate is agreat video application.

 The PSEye has been way more successful then the EyeToy has.

I call BS on that one.  The PSEye has not sold anywhere near what EyeToy sold.

As for limited, I'm referring to the its use as a method of control vs Wii-mote.

 It should be way more successful when comparing consoles old vs PSEye Sold (its around like 3 million last I heard.... trying to get Hasbro to reveal me some info on EOJ sales... not having much luck with that).

 As for control, full body motion versus arms... I'm going to say the PSEye and to a lesser extent the EyeToy wins. 

3 million? I will need a source for that. I've heard at most half that and sales have tapered off to a few thousand per month.

You claimed it was already more successful, now you're claiming it WILL be more successful. I'd be ready to believe if you can provide a fathomable bit of logic behind it or a source for verification but at current it has not lived up to EyeToy's standards nor is it on pace to do such.