A response to the saying: "There's no one 'right' way to do things. There are different ways of doing something that are 'right'. So stop criticizing my chosen way of doing things -- you cannot prove that it is wrong."
For any question, there is a certain number of right answers, but an infinite number of wrong ones.
Likewise, there may be more than one right way, but that number is small in comparison to the infinite number of wrong ways.
Each right way is ephemeral and contingent, and has its own tradeoffs.
Each right way is dependent on your current understanding as applied to your current circumstances.
As your understanding changes with experience, and as your circumstances change over time, the way that is thought to right will also change.
Sometimes that means realizing that your earlier understanding was wrong.
The novice says: "My new idea cannot be wrong, because there is no one right way."
The master asks: "Is it more likely that I have a new way that is better, or a new way that is worse?"
The novice demands "proof" that their way is wrong.
The master asks which ways are "better" and which are "worse", and picks the best one for the situation.
Sometimes the best way is still "bad", but better than all the others; the master knows this, and does not defend it as "right."