It's because those workers aren't willing to accept the total absence of benefits and Third-World wages just to have a CHANCE at being competitive.
Well, that just illustrates my point: how can you be competitive if you don't even know that competitiveness is not the same thing at all as accepting third-world wages?
Suppose you make 10 gadgets per hour and get paid $10. A Chinese worker make 2 gadgets per hour and get paid $1.90 By how much should you salary drop for you to be as desirable as the Chinese worker. The cost of a single gadget you produce is $1 vs. $0.95 when made by the Chinese. You salary should drop only 5% --- from $10 to $9.50 --- for you to be competitive. These $9.50 are far above $1.90 that the Chinese worker makes. You don't have to accept the Chinese wages at all.
Please reflect on this. Perhaps that will make you refrain from repeating the leftist propaganda about "accepting third-world wages" which evil corporations supposedly want you to do.