You are cherry-picking data, and at times outright speaking out of your hat.
Salary distribution at T14 law schools is bimodal: you have a peak between 40-70k, and a peak around 150-160k. The average is NOT 160k, it's much lower, because a significant portion of graduates work for the government or for community programs (Columbia's average is high, but it's also the highest of all T14s). There is a finite number of jobs in big law, and the conditions are absolutely, disgustingly dreadful. As
@avgn pointed out, very few remain in a big law position for more than a few years (generally to pay one's debts).
And the median matriculant GPA at Columbia might be 3.71, but it's 3.93 at Yale, 3.89 at Stanford, 3.86 at Harvard, etc.
As for your engineering salaries, it's utter nonsense. A quick search shows ~150k starting including benefits for an engineering position at Google (your example), and around 200k for a senior position. To suggest that the average engineer with 3.7 undergrad GPA makes 250k out of school is absolutely laughable.
As for the rest: medscape shows an average of 195k for primary care last year, and 285k for specialists. Specialists ARE, literally, run of the mills. They constitute 70% of practicing physicians (and the number is growing every year).