Upvote:3
The answer to why armies don't like fighting at night is plain and obvious: if you can't see, you can't fight well in a pitched battle.
The hangup seems to be whether it's dishonorable, but you're paying attention to the wrong part of Livy. If you read him more closely, you'll see what he's really talking about:
Not by ambushes and battles by night, they thought, nor by pretended flight and unexpected return to an enemy off his guard, nor in such a way as to boast of cunning rather than real bravery, did our ancestors wage war; they were accustomed to declare war before they waged it, and even at times to announce a battle and specify the place in which they were going to fight.
Livy mentions three other examples aside from battling at night that the Romans found dishonorable. All three have to do with dishonesty. Livy is saying that the Roman ancestors didn't like the tricks and preferred to have their battles straightforward and honorable.
Night battles aren't really battles at all, but raids. The Romans have as an example two night raids that were highly criticized in antiquity: the sack of Troy and the sack of Rome, both involving sneaking in and killing people when they're asleep. This is what the Romans found distasteful, not the fact that something happened at night, but the fact that the night provided cover for conniving tactics as opposed to "manly" head-to-head bravery.
This is the reason that Fabius Maximus was also criticized: his incessant running from Hannibal was brilliant, but not "manly" or "brave" and therefore incompatible with Roman values.
I should also point out that Fabius Maximus' refusal to fight at night is unrelated to the above:
Fabius did not want to fight a night battle, fearing a Punic trick to draw the Romans into a battle over broken, uneven ground, where Roman infantry would lose their edge as their lines would be broken, and communication would be hampered. Hannibal had previously hoodwinked and destroyed two Roman armies at Trebbia and Trasimene and the cautious Fabius did not want his army to be the third. Thus, although Hannibal still managed to trick the Romans, the Romans only suffered loss of face but not the loss of another army.