The original question is well justified. At least one of the best-known brands of star-quad cable sold in the U.S. has unusually high capacitance. Cable capacitance forms a simple RC low-pass filter with the input impedance of any preamp or recorder, creating a 6 dB/octave rolloff starting at some (high) frequency; the only question is at what frequency. The higher the capacitance of the cable, the lower the turnover frequency is, and the longer the cable is, the lower it is as well.
With some types of microphones--it may be fair to say "many types" but I haven't tested this myself, so I hesitate to say--there can also be a huge increase in distortion at high frequencies because of the capacitive load placed on the microphone's output circuit. I understand that this applies mainly to microphones that use output transformers--and of course this, too would be a function both of the cable capacitance per unit length as well as the length of the cable.
Being in the U.S. market, the two brands that I've known about for a long time are Canare and Mogami. Unfortunately I don't recall whether one or both of those brands have this problem; I don't have their specs handy, nor the calculations that I made about the effect with long cables. But more recently I was surprised to discover that my engineer friends in Germany made no association in their minds whatsoever between star-quad cable and high capacitance. On checking further, I found that the star-quad cable types marketed over there simply don't have this problem! It's mainly U.S. audiophiles, it seems, who buy the expensive stuff with the worst basic engineering design, and consider themselves superior for it.
That all said, 50 feet isn't very long. The real problems come when you're operating a remote broadcast truck parked outside a venue, with 500' - 1000' cables feeding the mixing board.
--best regards