Then String Theory is rubbish because it predicts nothing?
Every single theory in science started out with some 'predicate knowledge' and based on 'intuition', scientists reached out a few leaps with some ideas.
Some proved right, many proved wrong.
Some took a while to come together.
"String Theory" is different - it was not based on 'intuition' or any predicate foundation.
'Strings' are a fantasy - just completely made up.
Some people took a fantasy 'new origin' and put tons of math around it.
Since then, they've never been able to map it to reality, or even conceive of an experiment let alone do one.
What it looks like is religion - not only in it's foundation, but in the behaviour of it's acolyltes.
How does a Priest react if you tell him 'God does not exist'?
How does a String Theorist react if you tell him 'There is no String Theory it's just your imagination'.
Perhaps in the greatest of ironies, I actually believe God is more likely to exist than String Theory (!) or at least, there might be some kind of actual spiritual reality to our existence.
Strings? It's just an idea that snowballed into something.
How you come up with ideas and directions is a mystery. It's luck but not just. Kinda like investing.
Feynman also just described that step as "Guess it".
Its not clear at all that our institutional organized science process (grants, papers, academic positions and evaluations) correlate to better success at finding out stuff.
The ethos is simple: all scientific models are judged by their predictive power, and nothing else. If your model does not make accurate predictions, it is wrong, period. Nothing else matters.
I agree that there is no single "method" that guarantees that models will satisfy the above criterion.