Your profile says you live in Canada.
That's Honda's fault if a Civic costs as much as a BMW in Korea.
There is no protection when the tariff is 0%. Heck, Toyota stopped shipping Camry from Japan and is now shipping from Kansas instead.
No, it has to do with pricing on high-end models. Korean automakers charge its high-end models less in the US because they are a new entrant and need to build a market share. Accordingly it is possible to save upto $10K for some $40~70K models like Genesis and Equus via the re-export. For models like Elantra, Sonata, K5, and Azera, there is no price difference between the US and Korean market.