In the Orthodox Jewish view why do some Jews choose to not keep kosher?

Every religion has its non-observant members.
1) Non-observant Jews may be under peer influence.
2) Convenience; desires. No one wants "bothersome" rules.
3a) Lack of proper information. People have inaccurate notions about their religion.
3b) Lack of Jewish education.
4) Unfortunate experiences. Someone who had a harsh religious upbringing or parent, may retain an unhappy feeling towards Judaism.
5) Many think that science, and specifically Evolution, have proved that there is no need for religion.
6) Intellectual laziness. Many people have simply never delved into the subject.
7) Stereotyping. People call us "religious nuts," etc.