No 18+ year old male is going to be caught dead playing a game handheld in public, particularly anywhere women might be present.
Playing games on the smartphone is more inconspicuous and gets the job done as far as burning 10-15 minutes of down time.
If the older/dudebros crowd wants to play a "serious" game that's what their home console and 50 inch TV is for at home, there's no interest to play big games on the road. The average older teenager/adult doesn't even have time to do that.
The overall entertainment factor of a smartphone -- with internet browsing, checking Facebook/Twitter/Instagram, text messaging with friends, listening to music, watching videos, and yes maybe playing the odd game of Candy Crush destroys the value proposition of a Vita to any adult which basically just plays games/videos.
Why carry a bulky separate device just to play games on, when the games are in some weird limbo where they're better than smartphone games sure, but they also cost 30x more but aren't as good as home console games.
People don't want "deep" games on the road anywhere IMO. Simple to play smartphone games that can entertain a person for 15 minute bursts is all you need. The traditional handheld is overkill, it's like a fast food restaurant having a $30 steak dinner on the menu with a starter ... no one wants that, they want a hamburger and fries ready to eat in 1-4 minutes for $6.
