It was the Christians, who were persecuted by Rome, who wrote the history (at least in our predominantly in our culture).
As someone who has read a lot of this, I feel like this is a distinction without much of a difference, and I believe I can argue it extremely well, because the form of Christianity was absolutely distinctly a Roman Christianity (we still call it that!), right down to where it was based and the laws it used (including laws which arguably flew in the face of Christian teaching). There's some nuance of course, but even as some pre-Christian Romans were indeed demonized by later historians, other ones were basically lionized as "honorary Christians" lol. And the Protestant/Catholic split has some impact, it's temporally limited, and by the 1800s, the "Romans were amazing!" freight-train is running full-speed. I think that's all that can be really argued here on ENworld due to it involving religion, but if you want to discuss further, I'm happy to via DMs.
If you read books like Roman murder mysteries (there is a whole genre dedicated to this), the issue of slavery frequently comes up.
I am aware, though only really have read some of the Falco ones, and they were ummmm, not exactly historically accurate, and in my view, are very much part of the tradition of playing up the similarities of Roman culture to the modern day (or to the 1950s, at least), whilst playing down anything too uncomfortable. I see the genre is still alive and well and busier than ever, and I'll be honest, I have no idea if recent books in it are more challenging to this "Just like us but with togas" view of Rome, or if they perpetuate it further, or it's a mix or what.
Even in the golden age of Hollywood: you have films like Spartacus which are about a slave revolt (which ends with a massive crucifixion on the Appian Way: this is not an effort to say the bad things of the Roman empire were not all that bad).
Absolutely, but I think there's a bit of subtext often found to the nature of "Rome wasn't wrong, it was just the guys in charge hating Christians that was wrong".
Re: Spartacus, I think one might contrast the BBC/HBO series "Rome" and the Starz Spartacus. The BBC/HBO Rome went about as far as you're "allowed" to go in criticising Rome before loud establishment voices start telling you you're being "unfair" and you need to "remember what Rome did for you!". Compared to Roman writings, it's actually extremely tame in the depiction of Rome. It's far more tame and safe and modern-day-like than the Rome Roman authors of that period or even later described. Spartacus is lurid, over the top, sex-and-violence, and yet... much closer to the society the Romans themselves described (even on specific points, I'm already going on too much but frankly whoever wrote Spartacus did more research than whoever wrote Rome, even if they decided to ignore it and hard on melodrama at times).
And re: Spartacus further, it's almost impossible to see him as anything but a deeply heroic figure. You have to work really hard. Voltaire said his war was the "only just war in history". But it's telling that, in the British establishment (i.e. the public-schoolboy-lead brotherhood of people who basically run the country - politicians, senior civil servants, bankers, senior media figures, etc.), during the 20th century were one of the few groups who didn't typically see Spartacus as a hero, but rather as some kind of idiot, and I think that speaks to the sheer level of indoctrination re: the importance and superiority of Rome.