tsnor :
(3) want to ship a product for people like me that prefer this configuration to a fully modular configuration
On a normal day, I would agree that modular cables are way overrated. Even if I had a modular PSU, I would probably end up putting all the cables in the case anyway just to make sure I won't lose any.
On the other hand, my PSU's fan started rattling intermittently a few weeks ago. If I had a modular PSU, I could get the PSU out, lube/swap the fan and put the PSU back in in something like 15 minutes. With hard-wired cables though, it will probably take me more than an hour to remove all the wiring tucked away behind the motherboard tray and put it back, so I decided to forgo the repair until it sounds more urgent.