"The sexy unknown"? People know what JD is, a great damn hitter. He can't field at all, but he sure can hit the hell out of the ball.
In '17, JD had an OPS (on base percentage + slugging) that was 160 points higher than Jose, in '18 it was 233 points higher than Jose, and this year it was 105 points higher. That's a pretty wide gap if you ask me. Jose had a nice rebound year in '19, but JD would provide the team with a bonafide DH for the first time since the shell of Adam Dunn roamed the premises, some desperately needed on base percentage (his OBPs the last 3 years are .376, .402, .383, guys on base more have a better chance of scoring runs), protection for everyone else in the lineup, and can be a great influence on the young hitters we have here/coming up (see Betts, Mookie).
It's not about "statniks"/advanced stat people trying to shame the traditional stat followers, it's about making the White Sox a better baseball team. Adding a high quality bat to a lineup that sure could use it makes all the sense in the world. His age is what it is, he's about 7 months younger than Jose FWIW, but as a professional hitter and not much of a fielder anymore, one would hope to project that he doesn't fall off the "wrong side of 30" cliff as quickly as a normal position player would/does. Jose isn't a good 1Bman by any means, but both of them could definitely coexist, and the both of them on a 2020 White Sox roster would make it significantly better.