I agree that the right to strike is a fundamental one.
However, you need to pick your battles.
You should strike as part of a proper plan to actually achieve something, not just strike for the sake of it to cause damage to your company, and nothing else.
The TWU made false claims as to the reason for the strike, and didn't have any actual logical demands.
The Engineers action was far more considered and part of a master plan to achieve a goal, and most unionised parts of the company supported them. This was the TWU throwing the toys out of the cot, and so have not enjoyed the same support.