For the same reason you have blind hatred.
Everyone knew the address they gave wasn't the final destination. It was a 50/50% risk just even considering sending them it in the first place. They aren't exactly legal so it's not like you can take them to court. If it was just 1 delivery stop, Nintendo could just trace it back to them and boom no more gateway. It was probably forwarded at least 3 times from customer to reseller to middle man to to middle man and THEN to Gateway (all through china so you know how long that could take).
Both possibilities could have happened:
A) Gateway got it, didn't care to send it back and kept it.
OR
B) It never reached them period. Who's to say their middle man "accidentally" forgot to forward it to them. Happens all the time.
As for the trust, besides
retrofan_k and the one person he mentioned, no one else is complaining about stolen 3DS' even though I remember quite a few sent them bricked units (
Devin included). No system is perfect. No offense but that's not enough to get your pitchfork and torches just yet. I believe retro got the short end of the stick no matter what happened though.