When is 'starts with a conclusion and has been trying to fit the evidence to it' a bad thing? A lot of physics discoveries started with a hypothesis, then scien

When is 'starts with a conclusion and has been trying to fit the evidence to it' a bad thing? A lot of physics discoveries started with a hypothesis, then scientists tried to set up experiments to look for empirical data to confirm the hypothesis. If that's your only objection to these theories, maybe you're starting with your own conclusion yourself.