They used it because everyone uses it. It's more that this is a marketing issue coming from the massive JH3A debacle. Remember the original JH3A vaporware design paid for by the pre-order money of head-fi'ers was going to use active crossovers to have perfect phase alignment. That went belly up and hey presto Jerry says look over here now the new jh3a doesn't need those active crossovers and it's even better. The jh3a likely isn't selling well* so now hey presto now even the normal jh13/16 has this amazing new thing that nobody has called FreqPhase (which just so happens to be a form of something everyone has).
Again, it's fine to enjoy the new jh13, but my comments are completely correct: Jerry is claiming he's doing something special when in fact he's doing something everyone does already. "We do something everyone does but we think we do it incrementally better with no real evidence to show that we do so" didn't pass Jerry's marketing team, I guess. Jude has the new JH13, but unless he's willing to say that it's better than another Head-fi sponsor's product, say the UE PRM, then I would say that simply saying "OMG!" isn't very convincing, as "OMG!" gets said a lot on head-fi, with all respect to the people saying it.
*It doesn't really make any sense for Jerry to undercut the jh3a. There's little reason to buy it now.
To answer your question about the JH13 Pro versus the UEPRM: In terms of tonal balance, I prefer the UEPRM--I tuned it for me. The whole image is better centered on it for me than any of my other headphones, because I tuned it with the differences in my left-right hearing in mind. In my opinion, though, the JH13 Pro has unquestionably better detail retrieval, and better individual instrument placement. Again, the new JH13 Pro is among the most detailed of all the headphones I have here, regardless of form factor.
To answer another of your questions: The JH3A also benefits from the implementation of the new earpiece designs.
Even though a visual inspection doesn't explain it all, you'd see upon physical inspection that there are things about the freqphase earpieces you haven't seen before (unless you've already seen freqphase earpieces). You keep claiming that it's the same thing everyone else is doing, but it's not. There are no doubt IEM manufacturers share some common goals, but how different manufacturers go about getting to those goals can differ--there's definitely something different going on here.
Kunlun, you're quick to offer not just an opinion--but an impassioned slam--of a product you haven't even heard. That's something I won't do, and you should consider that, too. You really have a sensationalist bent, not to mention an obvious issue with JH that reads to me as a very personal thing--you carry it into a lot of posts, in a lot of threads. If I was to have a spat with a manufacturer, I would recuse myself from discussions of their products (which I have in the past chosen to do), and you should consider that, too.
I'll let this thread get back on topic.