Yes, they are wrong. With the right grounded LPS and isolator on the right router or switch, the wired solution should be superior or at least identical. If it's identical, why put all of this unnecessary hardware in the chain?
This is where we are talking apples and oranges. If an optical to Ethernet converter has a better power supply or better output stage than the router or switch, then it will sound better. That is probably what is happening. The solution is to make the wired solution sound better by powering with the right grounded LPS and the right isolator and using the right router or switch. These devices are not all equal in performance. My own router sounds better than my Cisco switch. The isolator actually has a small effect compared to the grounded LPS BTW.
Steve N.
Empirical Audio
Hmmm. In my experience the fact that glass is not polluted by network noise or emi/rfi is the key advantage and it is not subtle, all else held constant (i.e., switch integrity, lps power supply, proper ground etc.).
Your highlighted comment in bold above seams somewhat backwards to me. You are actually making the system more complicated (by adding the custom components you reference) not less and the best outcome you can hope for is still not as noise free or emi/rfi protected as glass. There is no reason to use anything but a standard switch, router and power supplies on the upstream end of the glass media converter. All of this is completely isolates as nothing but light moves through the glass representing digital data only. None of the noise you are trying to avoid through a lot of custom stuff gets through. Then add a very good power supply to a very good media converter on the dac end. I had YFS do my LPS custom to match my excellent Transition Networks media converter. (Measured ripple noise is .1mv.) When people argue bits are bits so network components don't make a difference we both agree they are obviously wrong because they ignore electrical noise on the grounds and in conductors. But with glass noise is zero.
Furthermore, for people like me who have a completely isolated electrical systems for audio, it is essential to eliminate extraneous conductors from entering the system to not just minimize outside electrical noise but to also avoid ground loops.