As opposed to a past period when they wanted a workforce that wasn’t available and disposable? I’m glad you mentioned Marx, because he was calling that out as primary desirable criteria for labor pools in general. A constantly available reserve army of labor and disposable workers is exactly what capital depends on to keep labor costs low. Hence the fundamental need for labor to organize and cooperate to counter the inexorable push of wages to zero (or its subsistence equivalent), or unemployment.

I’ll admit I’m probably unnecessarily nitpicking you saying, “employers today”, though. I don’t think I’m voicing a fundamental disagreement here. I do, however, really like your phrasing of JIT employees.