I think we should shame people for that: A nation is like a big family. You're essentially saying that you don't think that you should be able to talk to your own family in their language.
And that absolutely should be shamed, especially when you’re talking about a society like Japan that places high value on individuals acting in ways that make things easier for people around them and society at large.
I personally love learning languages and am that person that tries to learn a little bit and communicate wherever I go. I does seem to be a hot button issue here in the US. I think people have different expectations. You hear stories of immigrants from the early 20th century that would force their kids to only speak English so that they would get on well in society. It seems like a difficult topic here around heritage vs managing in a society, especially for kids.