Because software isn't the only industry critical to an economy, others are too. You can argue that pay=value to the economy but in practice, you can't equalize value and pay across all industries. Here is an extreme example: no matter how good a high school teacher is at teaching and innovative classroom management, no school would pay them 300K a year to teach because the average salary for this role is 60k. A more realistic example is a biotech PhD scientist with years of experience and proven impact in pharmaceutical industry. You would be hard pressed to find a company willing to pay this scientist 300K a year (avg salary for principal reseach scientist in SF is 200K).

Value and pay aren't the same across industries. Someone can still contribute the same value but the field they are in simply doesn't have the economic profitability required to pay them the same way software does. In fact, software is the anomaly in compensation. Making a policy that benefits only one type of industry over everything else is simply bad policy.