It is ok to (tactfully) criticize your former employer during a job interview, amirite?

I think a good way to say it is by saying you prioritise ‘xyz'. For example ‘Whilst my previous job was fulfilling in many ways, I value a safe work environment that follows ‘insert general safety protocol name in your field' and feel it was time to develop my skills in a company that could offer that'.

I've found that works

I've done this very thing, and yes I go the job. It's valid to criticize, so long as you remain tactful and professional about it.

There are many employers who are 100% looking for yes men who roll over and do whatever is asked of them. So as long as you can afford to (potentially) not get the job, sure.

I agree that it's important to be honest about why you left your previous job, but there's a difference between being honest and bad-mouthing your former employer. The key is to remain professional and focus on how the experience taught you valuable lessons and shaped you as an employee.