This other guy is saying it in a crass way, but his point is kind of accurate at the heart of it. There are ABSOLUTELY a ton of employers/companies/bosses that will treat their employees like garbage and will have every reason to leave their job. To just dismiss someone because they say they left because of management or job conditions is doing a disservice to the applicant. Sure definitely follow up on it and see why they left their last job and if they seem to be bullshitting or are bringing up bogus reasons for leaving than by all means dismiss them, but if their reasons are legitimate and would be something you yourself would consider leaving a job for or could see it being a reasonable reason then they shouldn’t be dismissed for it.