its good they speak your language but you cant speak theirs
They learn English because they need to. We learn no other languages because we do not need to and we have no need to learn the local language because everyone here speaks ours.
Please don't trot out this tedious, repetitive and narrow-minded line about some sot of superiority because they've taken the time to learn English. Only the silly and shallow-minded buy into that one.
If they'd learnt a second language as adults, that'd be something worthy of a nod of respect. Learning a second language as a child is no big deal. People do it all over the world - where there's a need for it.