The situation is that the FTLs- which are there to protect them...
I disagree with the bolded part here. Flight and duty time limitations are not there to protect the crews, they are there to ensure a safe operation. Flight time limits are not to do with industrial relations, they are fundamentally to do with safety and are there for the good of everybody, the crews, the company, and the passengers. The crews are protected by whatever lifestyle clauses they've negotiated into their contract, not the FTLs.
Given that they are not there to protect the crews, there is no discrepancy when they prevent crews from getting home, the limits are working exactly as intended, to keep the operation safe. That is why if the option of an extension arises, the Captain must be satisfied that crew is fit to perform the duty.
Nothing to do with protecting the crew and/or letting them get home, everything to do with keeping fatigue down to a safe level while also allowing for some flexibility IF the crew feels rested enough.
Whether the limits are actually appropriate is another matter entirely
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