This is going to be a somewhat difficult question to answer because historians are generally not preoccupied with the question of determining whether people were good guys or bad guys. It is not a question that many historians find particularly interesting (speaking for myself I suppose) nor is it one that the tools historians have are well suited to answering. The role of the historian is to understand that past--or something like that--not to judge it. This is not to say that historians cannot or do not judge the past: for example, I personally find the sack of Carthage by Rome to be a horrific atrocity that inflicted unimaginable misery on countless humans. But making statements like that is not something I want to spend my day doing.

This is not to say that historians have not considered the question of how we should talk about the ways we talk about the past. I will however leave a more detailed response to this to others, as I do not really think Classics has done a great job about this and so I have not received the training, but I did want to sound a note of caution regarding the whole idea of "the mores of the day". We can return to the example of the sack of Carthage: one can say that while it was severe, it was in line with the practice of the day, and so it is not to us to pass judgement. This is, I suspect, a more or less workable way to understand the perspective of Scipio Aemelianus and the Roman soldiers involved. But there is also the victim's perspective which is being erased in the assumption of a hegemonic "morals of the day" is that of the Carthaginian--would somebody who just saw their friends and family brutally murdered and the future possibilities of their life extinguished as they were marched in chains to slavery in a foreign land simply view this as fair, within the morality of the day? We have records of only one of these perspectives, and that is the one that is used to build what we consider to be "the morals of the day".

And occasionally we do have small cracks of light into those other perspectives, and they can be quite disruptive to what we say were "the morals of the day". For example, we might say that we would now consider the ill treatment of women in marriage to be simply the common practice of the day, the past, after all, is a foreign country, they do things differently there and we cannot judge them for it. To be more specific, China during the Zhou Dynasty was certainly a misogynistic society, and so we cannot "judge" them by "modern standards" in the regard. But also from that period there is a text called the Shijing ("Book of Songs"), part of which purports to be a sort of Alan Lomax style collection of folk verses. Several of these are written by women, and I suppose you can see where I am going with this:

Zip, zip the valley wind,

Bringing darkness, bringing rain. 'Strive to be of one mind;

Let there be no anger between vou.' He who plucks greens, plucks cabbage

Does not judge by the lower parts. In my reputation there is no flaw,

I am yours till death.

Slowly I take the road, Reluctant at heart. Not far, no, near;

See, you escort me only to the gateway. Who says that sow-thistle is bitter? It is sweeter than shepherd's-purse.

You feast your new marriage-kin,

As though they were older brothers, were younger brothers.

'It is the Wei that makes the Ching look dirty;

Very dear are its shoals.'

You feast your new relations, And think me no fit company./ 'Do not break my dam,/ Do not open my fish-traps./ Though for my person you have no regard,/ At least pity my brood.'

Where the water was deep

I rafted it, boated it; Where the water was shallow

I swam it, floated it. Whether a thing was to be had or no

I strove always to find it. When any of your people were in trouble

I went on my knees to help them.

Why do you not cherish me,

But rather treat me as an enemy ? You have spoilt my value;

What is used, no merchant will buy.

Once in times of peril, of extremity

With you I shared all troubles. But now that you are well-nurtured, well-fed,

You treat me as though I were a poison.

I had laid by a good store, Enough to provide against the winter;

You feast your new kin,

And that provision is eaten up. Then you were violent, were enraged,

And it gave me great pain.

You do not think of the past;

It is only anger that is left.

(Labeled as 108 in "Marriage" in Arthur Waley's translation)

This is precisely the perspective that gets erased with blanket statements about "the morals of the time". We can say it was a misogynistic society, but the woman (or person adopting the literary persona) certainly does not view it that way.