I guess i'm a bad DIL too. I'm foreign and refuse to dedicate all my time to learning the language, I'm outspoken, and just a bit weird (we like to live in other countries and the kiddo is home schooled which is alien here, as is mildly crunchy parenting which suits our family but is considered extremely suspect).
My poor MIL really has no idea how to answer questions from other people about why we live the way we do. But she tries! Oh she tries! And I love her to bits for doing her utmost to understand our weirdness and learning how to stop feeling like she should justify anything to anyone.
She's even stepping down from her matriarchal role after basically raising a brood of younger siblings as a child herself, parenting her own parents and being the driving force in her children's lives.
After having to go NC years ago with my dangerous mum it's a lovely thing to be in a family who don't always agree but always accept.
I've learned a lot from her about how to meet halfway with people who have a good heart and truly want to find a middle ground.
wow long post sorry. Short version: some of us like our MIL even when we're very different and a bad DIL