I've seen this sentiment quite often on these forums by many users. It intrigues me. I assume it is because of the small screens historically, but with today's handheld consoles that's pretty much not a problem as the larger screens scale well with the shortened distance from the user and it isn't that essential. Otherwise, it could be the type of games, but even then the Vita has many console-like offerings and the 3DS has high-budget epics as well. Finally, I thought of the controls, but the Vita is quite well-adapted for console players, and the 3DS controls tend to work with its library.  So why does handheld gaming turn you off?

*Note this is purely a curiosity of mine, as I don't really segment handhelds from television or monitor set-ups: to me they are all very much aligned. 

Because Handheld gaming eats up my time and is too convenient to use.

For the last couple years for me, Handheld gaming > Console Gaming
I love being able to do more than one thing at a time, like watch tv, while playing some Pokemon, or Mario, or level grinding in an JRPG.

Grew out of it, but some things about it surprise me from time to time. Everytime I feel like buying one my body kind of pulls me away and says "waste of time".

Quite simply, I prefer the games available on home consoles.

There are a few Vita games that have my attention, maybe I'll play them on Vita TV.

If you dismiss handheld gaming, your not a real gamer.

Cant compare to console or pc gaming. That's why I never had interest in it.

Only good game series on handheld is Pokemon and I was told I'm too old for that so I don't handheld game.

Before the 3DS I didn't care about handheld gaming in general (didn't even played with my DS all that much). Now I'm in love with my 3DS and I even use it more than my PC and Wii U (although the Wii U is because I only have 1 game for it )

I prefer console games, but handheld gaming is essential for a healthy gaming diet.