What I don't get is why the rebooted series really love them.
Romulans deserve more love. They've never gotten enough.
Now, they've become the new Klingons, where they were everywhere in TNG and DS9.
Go back to TOS, TNG, DS9, VOY, and ENT and count how often they appeared. They're a whole lot more front and center than in the past.
Just for reference (I didn't do any post processing, so I think this is missing Star Trek and Star Trek Into Darkness and the ordering/grouping/formatting is slightly different. But this is a nice way to get a rough comparison.
https://memory-alpha.fandom.com/wiki/Romulan#Appearances
Appearances
This list contains 84 items (show all)
ENT: (5)
TOS: (3)
TAS: (3)
TOS films: (3)
TNG: (21)
TNG films: (2)
DS9: (16)
VOY: (6)
PIC: (20)
LD: "Veritas"
DIS: (3)
versus
https://memory-alpha.fandom.com/wiki/Klingon#Appearances
Appearances
A list of all appearances of Klingons (excluding appearances of Worf and B'Elanna Torres).
This list contains 148 items (show all)
TOS: (7)
TAS: (2)
Star Trek films (8)
TNG: (31)
DS9: (49)
VOY: (14)
ENT: (11)
DIS: (18)
ST: (1)
LD: (6)
PRO: "Kobayashi" (hologram only)