Because Sony milked it too soon. Yeah Mario has a lot of games, but it did not start out that way

You guys are using the word mascot way too euphemistically. I guess Blinx the Cat is Microsoft's mascot?

Mascots have been dead since the 90's.

Edit: Oh and I love how LBP's floaty mechanics are being slandered by the same frauds who probably defend and welcome the broken, buggy, piece of trash known as Super Mario 64 with open arms.

Master Chief, Nathan Drake,Marcus Phoenix and Kratos are all mascots.  Granted they don't wear a red hat and eat mushrooms but that is exactly what they are.  Halo ODST did'nt sell well because it did'nt have Master Chieft. Gears of War Judgment flopped partially because it did'nt have Marcus.  

So did MGS3 sell less than the others because Solid Snake wasn't in it?

But anyway, don't get me wrong, they are poster boys for their respective brands, I mean in the context of an end all, be all, de-facto mascot.

Sackboy didn't catch on because the main selling point is creating your own levels and creativity in general and your average gamer could not care less. Sony catered to the online community/ hardcore fanbase and it failed.

I jizzed over Super Mario 64 back in '96 and I loved it on DS back in '04 but I watched a Twitch 120 star speedrun last night.  The mechanics are still solid and it broke new ground back in the day.  It's not so great now.  I can respect its achievements though.  It ushered in a lot of stuff we still have today.

LBP is a good game and it's gorgeous to look at.  I think it would have done better if Sackboy were defined, though.  It was a design choice but I think it hurt the game more than it helped.  And the game IS a bit glitchy and the mechanics floaty but I can forgive it.  It's trying to do a lot of things at once.  Any game that has realistic physics is going to have unexpected results sometimes.

He was made from a dirty masturbation sock. Not really fitting for kids.

Believe me when I say, I wanted to like the game, for years, as an avid SNES enthusiast no less. I suppose what separated the opinions were those who went straight from the SNES to the N64 to those who had already played Tomb Raider, Jumping Flash (hugely neglected I might add), Crash, Nights etc. on the PS1/Sega Saturn.

Interesting you bring up the DS version though, because IMO that's more along the lines of what the game should've been...

Don't confuse backstory with character. You don't need to have a love interest to have character. He's obviously afraid of a lot of things - ghosts, death, etc. You see him being afraid a lot of times during the games.

Played SM64 a few years ago on emulator. Yeah.... no good. I rarely ever not finish a game but I couldn't see myself going back to it after a few hours of mucking around.