I'm glad that didn't get made. The Romulans aren't that bad.
I agree that it probably would've been mentioned if the Romulans had decimated Vulcan and nuked Tellar and sent a black hole into Andoria, but remember that we live on a planet with Germany as one of the senior members of the European Union, only 70 years after they fought a massive war with everyone and practiced the worst ethnic cleansing we have seen.
The Romulan Star Empire of the 2150s is not the same as the RSE of the 2260s or the 2370s. Just like Germany of the 1940s is not the same as Germany of the 2010s (or, for that matter, Germany of the 1910s).