There's really no surprise that the FAA hasn't fixed this.
You see, as the article explains, the FAA regulates airlines and airlines use leaded gas. Inhalation of lead causes decreased IQ and diminished intellectual capacity. Since FAA regulators have to spend substantial time around airplanes and leaded gas, they have become a bunch of bumbling idiots. It's a Greek tragedy really.
Barely any airline uses leaded gas anymore, exception being small and/or specialised outfits like those that fly WW2-vintage DC-3s in Alaska and so on.
Airlines have long enough flights and can pack them enough that the overhaul economies of turbine engines work in their favour (they work very not in favour of private aviation).
What overhaul differences? Piston engines are overhauled per amount of hours worked, period. Turbine engines have overhaul times specified both in hours worked, and cycles, and you have to overhaul when you reach either of those limits, whichever comes first. A cycle is engine-start to engine-stop. In private aviation you're going to shut down the engine often, so you can quickly rack up cycles that end with you having to send your engine for expensive overhaul.
You see, as the article explains, the FAA regulates airlines and airlines use leaded gas. Inhalation of lead causes decreased IQ and diminished intellectual capacity. Since FAA regulators have to spend substantial time around airplanes and leaded gas, they have become a bunch of bumbling idiots. It's a Greek tragedy really.