TLIK, the words people use reflect values. so, if we adopt wrods without thinking, we adopt and propagate those values.
People who value word “frum” typically include in that those who are not nice to other people or break societal norms. Those who value “erliche” start shouting “hillul hashem”.
Chofetz Chaim, for example, writes bitterly that people consider some aspects bein adam l’havero “etza tova” rather than halakha that is as strict as kashrus.
Chofetz Chaim also brings another dichotomy: “people say that in our times, one needs to be frum, but I say – you need to be klug, klug, and then frum”. That is, acting with sechel is the first defense – and the second – and chumros and obstinance the third.