For those wondering, capacitance is mainly contributed by the type of passive shielding (thickness and material) used. Generally, the thicker the shield the higher the capacitance, which as explained already, is not desirable. However, shields are needed to block out RFI and EMI; the thicker, the more effective. Like everything else, there's always pros and cons.

Anyway, the concept of making a good cable is simple. It's just striking the right balance between the forces that results in impedance (Z). That's where all the mumbo jumbo techincal sh1t starts. An example to the high capacitance problem above would be to attach filter networks, or go for active shielding.

Do note that the guitar cable is generally short length, carries a signal that is limited in frequency range, and is generally not used in electrically noisy environments. That said, I doubt all these theories can be applied.