Some datasheet specs to put this in context:
Alps RK27 series - £8.78 each at 500+ quantities, Gang error <3dB 0 to -60dB, <5db -60dB to -80dB
Bourns PTD90 series - £0.92 each at 500+ quantities, Gang error <3dB 0 to -40dB, unspecified at greater attenuation
Even the 'poor' performance of this unit is within the spec of a standard high quality pot range. Manufacturers would need to test the pots if they wanted a tighter match - not unprecedented, but probably uncommon at this price point.
Also note the lack of standard for taper letter designations - for Bourns the A[1-6] series are log tapers, while the B series are symmetrical about the centre point. Vishay do something else entirely.