“and it’s not that they just supress their evil natures. “
An evil nature has nothing to do with whether or not a person is frum – either FFB or BT. People with evil natures may be found in all walks of Jewish life (and non-Jewish) and “good” natures may also be found in all kinds of people. Luckily it seems that there are more people with good natures – in all kinds of Jews. This is not exclusively found amongst the frum.