If FCA productizes them then I assume they have to do full FMEA and safety testing whereas it’s largely caveat emptor for aftermarket doors.half doors were standard on all Wranglers up until 2007 with the launch of the JK. And available on the JK Sport and Rubicon as N/C door option. If you have never owned an older YJ, TJ with half doors that's ok, for us who have and still do they are quintessential Jeep. Unzipping windows may not be your thing. But nothing lost by FCA to offer them like they did on the JK as a N/C option when ordering or in the accessories catalog.
As for R&D time and money developing them.....please how much R&D time and money was thrown at the fold down windshield???? Is it cool I guess but I seriously doubt 1% of JL owners have ever did it let alone took a drive with it down unless you love catching stones and bugs in your face.
Offer it and for those who want them they will get them, other than that to each their own,