“Joseph, I think everyone would agree that your Shabbos-driving cheeseburger eater isn’t frum. But what about someone who watches TV and movies, has an unfiltered smartphone, and doesn’t check vegetables for bugs?”
or someone who wears short skirts or speaks Loshon Hora?
According to the Chofetz Chaim, the issue is someone who deliberately transgresses a Mitzvah that everyone knows about many times. It seems to me that most not-Frum people would not fall in this category since most of them do not know about the Torah and Mitzvos. And it would seem to me that some Frum people would fall in this category since most Frum people know that you are not allowed to wear short skirts or speak Loshon Hora. I wonder though if it would make a difference if you know that the person is working on themselves.
In any case, the Chofetz Chaim clearly states that you are only allowed to speak about them if you fulfill all the conditions of toeles, which is very unlikely.