OP is right to some extent, if not happy, you know where the door is. That applies to those employees that have NO pension benefits.
The rest of us, with pension benefits it can make a huge difference to stick it out. Especially in the years running up to your 30th year. People complain, because they want to get to their 30 years.
Some 25-30 years ago, it was unthinkable that we would not be able to continue working with this company and retire with the full learnable pension benefit. Today, it is just as unthinkable to be able to do it again.
Many of us, are just a few years from earning that full benefit, while under constant threat that the company will lay us off, with no way to get to that full pension benefit. That is what the complaints are about