I get your point, but if soldering is the only problem, just get a spring loaded solderless connector for JTAG pads? then it is about the same as USB for many more people?
In one case, I plug a USB stick into a working computer, which virtually everyone has already done at some point before, run a utility included in Windows[1], and maybe download and drag some files around to copy them. In the other I do a whole bunch of stuff that isn't common to any neophyte or even most advanced computer users.
1: https://www.google.com/search?q=how+to+make+a+bootable+usb