Yes this is a BAL vs UNBAL conversation. Real quick ill just say BAL is for long cable runs, that's why you always see them used in professional stage gear. The balanced circuit is a more complex one and for home audio, depending on the engineer/designer they my choose to keep the circuit more basic for whatever reasons...In my listening over 35 years I do not think balanced "sounds better" than unbalanced. Many quality components have one or the other or both? Turntables are simple therefore you see mostly unbalanced outputs. Why take something that works great and make it complex by adding balanced circuitry? IMHO.
If you have ever wondered why tonearms have that ground wire where no other single-ended connection seems to need one, the answer is that its a balanced connection that is being set up to run like a single-ended connection.
Actually the real question here is why take a balanced source, and then convert it to single-ended and introduce colorations along the way? The justification for balanced operation is not long interconnects, it is a **lack of artifact** from the cable. It is the latter that allows the former, but really, length is irrelevant. Lack of coloration is the goal. If you have ever auditioned phono interconnect cables to get the one that 'sounds right' then you know what I am talking about. That is something you won't have to do with a balanced phono connection, unless it is improperly wired. It will simply work.
Our (balanced differential) phono stage has only 2 stages of gain, but works with nearly all LOMC cartridges. Most single-ended phono sections that can do the same thing have 3 stages. So which is more complex? As far as the signal is concerned the balanced is a simpler signal path and one that is lower distortion.
Most tone arms allow a balanced hookup. If you have a 5-pin DIN connection it is very easy- the ground connection (pin 3) is the shield of both channels and is the XLR pin 1 in both channels. If the arm has RCA output its still easy- the trick is to not allow the barrel of the RCA connection to touch ground or be the shield, as that is the job of ground connection (represented by the ground post). I can supply details; they are published in our preamp manuals which are a free download from our website.
Even the old BSRs, Duals and Garrards can be wired balanced without jumping through any special hoops.
We made the first balanced phono sections anywhere in the world. So I can tell you the reason that balanced phono is not more common has everything to do with the dealers who don't like to change the cable when they are doing auditions. This comes from 26 years of seeing that be the main objection; not from customers, but from dealers.