Why no support for PS Vita and mobile devices?

It's late, so I'll try to make this short. Basically, when a developer releases a game multiplat that includes the PS Vita, they tend to give more support (updates, DLC, and such) to the console versions of the game. My question is.....why?!

I ask this because sometimes I PREFER having my games (like ZoE and Sonic & ASRT) on my Vita rather than on consoles. Yet, I also want to use the same DLC or get the same pre-order bonuses as the console versions. And for it to release alongside consoles.

The same could go for some PC releases, too.

I just want some decent exclusives ffs. Right now there's no reason to get a Vita besides Wipeout and a few JRPGs that won't make it outside of Japan and NA.

not enough consumers. and they will not do it of the kindness of their heart. ill break it down even more. lets say they spend $1000 to develop a dlc for vita this includes labor of employess ect final cost $1000 and it took a period of 3months, and only two people baught it within a period of six months. thats why.

Because software sales for handheld games arent good enough