In the construction industry, the contractor hires the subs who hire the illegals. If INS shows up, the only person who gets nailed is the sub.
In the end the illegals may or may not get arrested or deported and the sub (green card) takes the heat. The contractor/company just has to scramble around to find another crew.
Not much incentive for the company to worry about “hiring illegals.”
According to current law, it is illegal for them to work here and they should be arrested and deported. That is the law. If it is not enforced, then who should be held accountable?