Because it's largely true. They are there to let corporations use the law as a tool to make higher profits.
They make so MUCH money not because they can convince corporations that they need to drop unfair terms from employment contracts but because they can figure out a way to get them included. That makes them very profitable as well as unethical, hence their high wage.
If all they did was the kind of thing you're talking about - ensuring compliance with the law rather than creative ways of getting around it - their pay would be average or low because they are not making the company money.
>In particular I'm unconvinced by the link drawn between "talented poet-musicians" failing to get their recording contracts renewed and maldistribution of incomes, as if the 99% were unable to afford to patronise poet-musicians rather than seeing no value in doing so.
Really? I'm convinced. Are most Americans financially secure enough to be patrons of the arts? HELL no. Rent, healthcare and education are #1 priorities because they're so fucking expensive.
Why are they so expensive?
Because the corporate (debt) beast needs to be fed.
Poet-musicians seldom play for such high stakes, though ones that can't sell enough albums to pay the recording costs or get enough live gigs to feed themselves haven't necessarily left their audiences feeling happier on aggregate.
It's really easy to believe that certain corporate lawyer jobs have no social value, or negative social value. It's also really easy to believe that somebody who enjoyed being a "poet-musician" is rather bitter about the fact they now spend sixty suited hours a week wearing a suit composing boilerplate prose, and their whining about what a massive waste of time their job is isn't a particularly good illustration of misallocated resources. It's natural to believe that stuff you enjoy doing is more socially valuable than stuff you don't, but personal feelings of validation are an even worse proxy for social value than the market system.
In particular I'm unconvinced by the link drawn between "talented poet-musicians" failing to get their recording contracts renewed and maldistribution of incomes, as if the 99% were unable to afford to patronise poet-musicians rather than seeing no value in doing so. And funnily enough, if the poet musician suffered from being undiscovered rather than untalented, they could probably benefit from the endeavours of people involved in the drudgery of service sector "bullshit" jobs like A&R man, ad exec, or analyst for music retail platform.