True, but there's a bit more to the story.
What drove Hostess into the bankruptcy in the first place was bad management, lack of investment into their plants, etc., you know the usual. That management squeezed what they could out of the company, took their bonuses, and left the sinking ship.
They then brought in a new CEO, and he put out plan to right the ship. That included pay freezes/cuts. Two of the unions agreed to the new contract, and one of them double-checked the numbers, and they agreed management was not lying about this being needed.
One union refused. The union leaders recommend to their members to let the company go bankrupt, go to auction, and then the new owners would give them a better contract. Now, it should have been obvious that the new owners are likely going to be company in the same business, and like any merger, a ton of jobs would be lost. Indeed, that was the first thing that happened, where 2/3 of the plants were closed. These were well-paying jobs too, not something you can find baking just anywhere.
In conclusion, irresponsible management drove Hostress to the brink, and that one stupid union put the final nail in the coffin.