I really couldn't care less if the big 3 in the USA don't hire E3's. This is because even when working for what someone referred to as "low tier" US airline, they are much better to work for than the likes of Qlink/Jetstar etc.
I know this because of the 3 people I know who left the USA for an Airline job in Oz came back to the USA within 6 months. Now I also know people who went back and stayed but that was more because of pressure from family rather than job satisfaction.