There is no real simple answer to the question because I think it depends on what the objective is. I heard that high end new chains shouldn't be degreased for a few hundred miles, just lightly oiled. But after that initial period, I think the advice you received is very suspect. If any materials other than the components of a lube are in a chain, they are damaging the chain plain and simple. If there is enough foreign matter it is also damaging the rest of the drive train.

Modern high performance high RPM engines go with synthetics which minimize friction and residue of any kind. However, in the 50's, most 4 and 6 cylinder overhead cam sports car engines benefited from paraffin based oils because tolerances weren't that tight. Bike chains aren't precision devices and they obviously aren't enclosed either. So, they probably benefit from a slight waxy buildup and really clean lube. However, the more lube and "gunk" the more that harmful foreign matter will be introduced into the equation.

So, the questions are more in the realm of balancing performance vs component life vs maintenance workload. To me, cleaning the chain completely after every ride is the optimum answer. But, that is contingent upon how much time and skill one has with respect to re-lubing the chain. If the re-lubing is not accomplished correctly, the inner components of the links will not be properly protected and damage will be done to the chain by friction and heat buildup.

So, there is damage from foreign matter and there is damage from insufficient lubrication. The likely worst scenario is poor lubrication combined with dirty lube.

So, letting the chain have a little buildup and re-lubing without cleaning is probably beneficial for some folks based on their available time and the relative cleanliness of the ambient conditions in which they ride.
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