Why action games are bad for expensive handhelds (PSP & NDS I'm looking your way)

Alright, so you've layed down $150 - $250 for your brand new handheld system. You get all excited to play all the new games coming out only to find that most of them are action/sports titles. No biggie, more fun for the short attention span, you think. There's just one tiny little problem with this situation: sports and action games require lots and lots of button-pushing. Well, you may wonder "So what? I like to push buttons!". The real problem comes from the lack of one item: a replacable controller. With handheld systems, if your buttons become 'less reponsive' or just don't work at all, you need a new system not a new controller. So instead of $20-$40 for a new controller, you need a whole new expensive system. Ouch!

Seeing the 'smoke before the fire' can save you a bunch of cash, so here's a list of games that will go a little easier on those oh so precious buttons. Not a lot of blood and guts or explosions but still looks like a fun/diverse list.

Upcoming PSP Button-Relievers
Legend of Heroes
Popolocrois
The Sims 2
Tokobot
Metal Gear Acid 2
Harvest Moon
Talkman (US release ????)
Black and White
Field Commander
Pilot Academy
Lord of the Rings Tactics

Why no NDS games listed???? 'Cause I'll never own a NDS unless it is gifted to me. Sorry.
Two screens? One stylus? Why???