The huge amount of piracy, I have never seen so much piracy on a console.

There were so many games for the DS that the good ones were buried under a slew of bad ones.

Don't forget Trace Memory

Yeah right. That must explain why Bravely Default, Fire Emblem: Awakening, Tales of the Abyss and Kingdom Hears 3D sold well on the 3DS. (which even has a smaller install base than DS)

Other than the strong competition, the current and old handheld market is full of experimental and niche low budget titles with little to no marketing.

I never said they had the same people making up their install bases.  The 3DS released into a different climate with different people.

Too many DS games. And GTA games don't sell on Nintendo consoles.

130 of those 150 millions were copies that parents bought for their kids to play Nintendogs, Cocking Mama, and shovelware. And they only played for two months and got bored.

Ok, then where were these people during the DS era? RPG fans that bought these 3DS games were surley active rpg players during the DS generation. The PSP didn't get good RPG's till 2010ish (like Trails in the Sky, Birth by Sleep) so the DS had the majority of great RPGs in the beginning to mid and therefore themajority of RPG players.

The Dragon Quest games, Final Fantasy games, Chrono Trigger sold well on the DS after all. I think it's more about piracy and lack of marketing.

To be fair, there have been only two GTA games on Nintendo consoles: Chinatown Wars for the DS and GTA for the GBA. Neither platform was really suited for GTA, and those are the top down perspective titles, and they sel way less than the 3D ones. Rockstar has really never tried to sell GTA on Nintendo systems.