This is like arguing that state governments have ignored the rule of law because some people get away with speeding. Additionally, illegal presence (as opposed

This is like arguing that state governments have ignored the rule of law because some people get away with speeding. Additionally, illegal presence (as opposed to entry) is a civil violation, not a criminal one. And the law as written grants broad (indeed nigh unlimited) discretion to the executive branch in how administrative law is enforced and decisions are made, rather than mandating specific outcomes or methods. So I don't think your premise is valid at all.