I don’t know how many contracts IBM deals with, but the concept of a bench is very common in government contracting. It helps retain talent in an environment that’s more volatile than a typical office. Good for the company to avoid brain drain and hiring overhead, good for the employee because it’s a built-in safety net. Much better than your contract ending and immediately being out of a job, especially in today’s market
Longer Bench allowed only for consultant with security clearance as those are such a hard thing to come by. General govt work, they just let you go like in commercial sector.
Those are the positives. The downside is that the sales team presents you with really lousy contract opportunities and you are pressured to accept one knowing it is a crap assignment that isn't helping your career growth. And you can be stuck on one of those for years!
I don't think they're objecting to the idea of a bench as an ultimate fallback; I think they're objecting to the idea that there isn't, during such "internal layoffs", a default automatic reassignment of all headcount to other teams. In such cases, you would only land on the bench if you refuse the automatic reassignment.