I agree that it should be voluntary but the "I want whats mine" attitude is one of the most effective weapons the company has used to make sure that none of us gets what we should. You are fighting your coworkers over ever shrinking crumbs instead of fighting the company for a bigger slice.
The company's exploitation of our weaknesses has cost us dearly. Over the last five years I've basically worked a year for free. Over the last twenty two years I've never officially been laid off but my lifetime earnings would seem to indicate I've lost several years of pay. Basically the company is getting the benifits of a layoff without losing the labor. I'd much rather take time off, that I could sell elswhere if I so desire, than work for less. If we are forced to take some form of a collective wage cut then better to only lose the money, and keep the time.
