Mdd, on a practical basis, we must treat people who are lax with mitzvos bein adam lamakom as the normative halachos state. I.e., one who is not shomer kashrus obviously can’t have neemanus about kashrus, and can’t be a mashgiach.
However, as far as hating them, which is how this point of the discussion began, that is not something we should do today. As far as whether the RBSH thinks they are reshaim, that is for Him to decide, and is not my concern. I am sure He takes each individual case and his circumstances and upbringing into account. I am sure He also knows that it’s been a long galus and hester panim, and people have lost faith along the way due to many tragedies, and probably some may have given up on Mashiach simply because they have waited too long for their yeshuah.
What about a person who has been davening for 25 years to find a shidduch, and now she still hasn’t found one, and is now too old to have children, and her lifelong dreams have been dashed, along with those of her parents who desperately want to walk her down to the chuppah, while they are still able to.
I am not one to judge my fellow Jews after all they have been through.