The Romulan losing their homeworld was barely an issue in PIC.
This is just flat-out false. The fall-out from the destruction of Romulus informs damn near everything about this show. It informs Jean-Luc's depression and self-destructive impulses, and his desire to get out there and start making a difference again. It informs Jean-Luc's feelings about the most important relationship of his life until then, his relationship to Starfleet (and therefore the destruction of his own self-identity in the 2380s, since he cannot conceive of himself outside Starfleet at that point). It informs the
six different Romulan factions we see in the show -- the Zhat Vash, the Tal Shiar, the Free State, the Reclamation Project, the Qowat Milat, and the Vashti refugees. It informs the basic setting of most of the show, the now-lawless borderlands between the Federation and the former Romulan Star Empire. It informs Seven of Nine's arc as a Fenris Ranger. It informs Federation political culture, as it struggles with its own nationalist/isolationist elements. It informs the strained relationship between the Federation and the Free State, as the Free State is clearly trying to establish a better relationship with the Federation than the Star Empire would allow. It informs the conflicts that clearly exist between the Zhat Vash, the Tal Shiar, the Qowat Milat, and the Free State government. It informs why the Free State is administering the Reclamation Project and studying the Artifact. It even informs the Riker-Troi family, as it ties directly into the death of their son and the slightly haunted life they lead as a result. The destruction of Romulus and the collapse of the Romulan Star Empire permeates and informs
everything about this show, and to claim it's not a big deal is just an absurd thing to say on its face.
And the Romulan military seems just fine and unchanged from TNG.
I don't know how you can say that -- we only catch a glimpse of what
might be the Imperial Fleet in the form of the ships that seem to be surrounding the Artifact to control traffic to and from it. The rest of the time, the Romulan security forces we see are Tal Shiar.
ETA:
Unfortunately, all the odd Warbirds were destroyed and the even ones don't arrive until Tuesday.
I'll show myself out.
Something interesting to think about: The ships in the Tal Shiar fleet in "Et in Arcadia Ego, Part II" looked surprisingly small -- honestly they look like they're barely any larger than a Boeing 747, so we're looking at ships that are somewhere in the range of 80 or so meters long. By contrast, a 22nd century Romulan bird-of-prey from the ENT era is 130 meters long, a 23rd Century bird-of-prey from the TOS era is 131 meters long, the 23rd Century D7-class Klingon ships they imported were 228 meters long, the
Mogai-class warbird from NEM is 604 meters long, and the
D'deridex-class warbird from TNG is 1,353 meters long. The ships in PIC seem more on the scale of the Romulan science ship from "The Next Phase" or the Romulan scout ship from "The Defector" (95 and 89 meters, respectively).
Seems likely to me that if the Tal Shiar can only muster ships on the scale of around 75 to 90 meters in length, that's an indication that its ability to project force is
significantly depleted from that of the Star Empire's Imperial Fleet.