Because anybody buying at an industrial level is wise to it being untrue at a gate length level. Plus it's easily available to consumers that the gate length isn't that size. Plus it's bullshit that at some level everybody buys, even Intel and TSMC in some roundabout way, at the highest levels for sure, though not at the ground level. At the ground level even eg 180 nanometer has virtues that 28 nanometer lacks, it's totally different things, different texture different everything, the graybeards know. They know. Then there's different radiation resistance but that's too obvious.

So if everybody believes in the nanometers, nobody cares.

Until you hit a wall.