I'll give you that Rossi is way better than Chandler, but that's somewhat irrelevant to my point. If you think the US is in the loss column in terms of quality exported quality imported, you're not paying attention.
And he hasn't chosen to be exclusively Italian, he's chosen to be an Italian national team player. He's got dual nationality, like probably a few million other Americans. He's still American. Why am I interested in Michael Bradley's soccer games? Because he's American. Why don't I complain about journalists and posters discussing countless other Americans playing overseas even though, unlike Bradley, most are not in the USNT? Because they're still American soccer players, and that's interesting to me and plenty of other people.
Rossi is a "traitor", and as far as I am concerned, no amount of word-twisting can change the fact. Rossi could have easily been a starter for the US from the get go. Chandler couldn't pick up the towels for Germany. A world of difference.
Rossi's motive to switch was his loyalty to Italy, despite being born and raised in the US. I hope he does not come back and play in RB Arena, or in MLS, but since he is a dual citizen, he has the right to do so.
If you want to make an interesting comparison, think of Enrico Fermi, the "father of the atomic bomb". He left Italy for the US for a darn good reason - fighting for democracy over fascism. Fermi had a darn good reason to switch from Italy to the US.