Rav Nachman of Breslov says that each time you do something wrong, you hate one person. Somebody you know. It's clear to me that all these people, all these fruma people woh hate people who aren't religious, have a problem. They did an aveirah, and therefore, they hate somebody. They hang their aveirah on someone who doesn't keep Shabbos.
Hatred comes from an aveirah.
Take Rabbi Levi Yitchak of Berditchov. Because he never did an aveirah. For the same reason. Now I want to say the deepest depths. When you see a Jew who hates another Jew, the problem is not the Jew who doesn't keep Shabbos.