well idk where your ears have been because i've heard and experienced the opposite.
i've used a 3DS for a few hours playing monster hunter, on the 3DS XL, and i never got eye strain. occasionally i would tilt my head too far to the side and it would kill the 3D effect momentarily, but that's easy to correct by simply readjusting my head.
also there's probably no significant difference in the strength of the screen compared to any other phone or tablet, because no one even mentions it, i have no clue who told you it was bad quality.
idk who you're aiming to convince here tony, but if you're making it that obvious how one-sided your opinion of the 3DS already is, no one's going to take your word seriously.