Other than a cable failing, why would anyone ever need to remove the cable from the ear piece?
Isn't that enough of a reason?
Personally, no. RHA's three-year warranty - as well as their track record in honoring that three-year warranty - leave me confident that I would be well-tended to for a period of time. Beyond that, I am not terribly concerned as I would probably have moved on to something else within those three years.
Besides, to introduce another connector is tantamount to introducing another point of failure. The stresses that can be exerted on a connection point vary greatly in nature, and are occasionally non-trivial. I would rather have something solidly constructed, than removable for versatility's sake. I've also had friends inadvertently lose earpieces (UERM, JH-13) due to cable removability. I know that is human error, but it was less likely to happen if the cable were not removable.
So no, for me, a [possible but not certain] cable failure is not reason enough. That said...
This is Head-Fi, and sound is everything. So if they wanted to introduce a swappable cable feature that lets me use a balanced cable, I would be most gratified.