Might have been worth it to try and save the Bison-hide industry in 1872. By not having the hunters kill every last bison they could find, until there were almost none left.
As a whole this post is too market-forces positive in my opinion. There are other concerns in a society than "do or die". Sometimes a market can become disrupted through forces outside of the industry's own control, and it becomes necessary for the state to intervene to not have undue damage done in a transitional phase. Such an example was the car industry in the US when the housing bubble burst. Now, GM and Ford and the lot were obviously mismanaged prior to that event, and in trouble already, but nonetheless it does seem like it was worth it at the time to ensure these huge companies didn't die entirely, as they are now back in the black again.
Certain industries also have an strategic importance over and beyond their "competitiveness" and impact on employment and profitability. The food industry is one such. That is why countries all over the world give their farming industry subsidies. They don't want all of their food sources to be entirely in the hands of other people and countries. That's probably worth a thought too.
So the answer is - yes, sometimes it CAN be worth saving "an industry", even if the prevailing market forces would have such an industry die off.