Well intentioned post. Though I never understood the "don't trash your employer" advice people often give. It's often the more empathetic thing to do in such situations.
One nice thing after a former employer goes bankrupt/execs get indicted for securities fraud is you are then free to trash your former employer (and I’d view with great suspicion anyone who didn’t).
In some cases (many, actually), you have to sign a contract to get your severance, and there's often a "non-disparagement" clause in there.
I also feel that it's just good common sense, too. Even if we are incandescent with rage, it's usually considered "unprofessional" to descend into name-calling. If others see us as "unprofessional," that can have negative impacts on our careers. It's usually just safer to be noncommittal. Doesn't cost anything, and likely saves a lot of heartache.
I'm fairly saddened at the reactions to this post. It did not prescribe anything that would really cause any harm, and is a basic "everyone knows this" aspect of relationship-building; done so, for centuries.