“I am not scared of girls”
“..Except my mother”
Let's be clear: The Ancient Greeks did a lot of 'war'. If they weren't fighting each other (Athens and Sparta), they were off conquering the world (Alexander the Great). So, as it would later turn out — they were also good at producing psychopathic dynasties like the The Ptolemies of Egypt and the Seleucids of the Levant — Greeks were proud that they were the first to study military tactics and strategy. It is why they had beaten the Persians and then conquered them.
So you would imagine, with this war-making ability, the Greeks would honour their war god, Ares. Yet — to use another word that is itself a gift of the Greeks — they were hypocrites. Surviving myths always portray Ares as a cowardly boaster who could be beaten by braver mortals and — in an insult the Greeks thought truly humbling — even by Athena one-on-one. If they were other tales about Ares where he came out victorious or showed he was a skilled warrior, they were not preserved. Instead, Ares has come down to us as a the good-looking beach bum with peroxide hair and a 'talent' for shameless self-promotion. In other words, an ideal contestant for Jersey Shore or The Only Way is Essex.
To other Ancient World rivals where the War God was usually honoured — and supplied — with human sacrifices, the Greek approach was a huge puzzle. The Romans who otherwise stole all the Greek myths for their own (with a name change), also adopted their stories of Ares' fighting failures. But they added one the Greeks didn't have, that Ares (or Mars, as they called him), was the father of Romulus and Remus, the wolf-suckled twins who had founded Rome. That was why (the Romans reasoned) they had ended up conquering all the great Greek cities and empires by the time of Jesus.
A Ram Confusion
Ares is not Aries the star sign of the head butting ram but they do offer similarities. Easy to anger like a ram, Ares was keen to 'butt' heads with anyone. On Olympus he was despised by the other gods including his father Zeus. Even his mother Hera showed little affection for her handsome meat head. The only thing that prevented Zeus expelling Ares from the Olympus was that at least he knew where his son was. It also pleased him that Ares showed no cunning or intelligence to do what Zeus had done to his father - usurp his position and rule instead. Ares was too dense for that type of activity.
Since he was short on the grey matter, any idea he could marry his half sister Athena was ruled out. The latter had pledged herself to perpetual virginity like a Girl Scout leader. The available goddesses were already married off or like Artemis, formerly like Athena a virgin but with a known liking for the company of naked nymphs. Ares would not have a look in there. He did however have an ardent admirer in Aphrodite. She had been (by Olympian edict) maritally shackled to Hephaestus, the metal bashing handiman who rarely washed and smelt like an iron smelter's jock strap. Ares and Aphrodite had then engaged in a busy affair that somehow produced a clutch of children (including the perpetual fat baby Eros) that her husband was unaware of until Apollo snitched on them and told Hephaestus.
Ares and Aphrodite were trapped in mid canoodle when Hephaestus sneaked up and threw a fishing net over them. Hephaestus invited everyone else on Olympus to come over and look at his guilty 'fishes'. Ares hated being laughed at but to get out from his predicament, he agreed to pay a fine to his brother but carried on with Aphrodite, just making sure they arranged their meetings at other locations away from Mount Olympus.
With no one at home to warm his slippers, Ares spent a lot of his time on Earth ravishing and grabbing female flesh to satisfy carnal desires. Unsurprisingly, a lot of the kids from such a father would often turn out to be brutal copies of their deadly dad. He didn't venture on his own, another sister called Eris Discordia rode shotgun on his war chariot. She had the cold, hard eyes of a fashion model and resented the time her brother spent with Aphrodite (as love conquers all) and couldn't abide her drippy-hippy niece Harmonia. Less work for Eris stirring up trouble and more time working out that Sudoku puzzle.
Ares had another sister called Enyo or Enya. She drove her enemies mad by singing Orinoco Flows on an endless loop. Accompanying them on their blood rampages were sons Demiphobos and Fullphobos (half fearful, fully fearful). They were supposed to be Aphrodite's kids but looked more like Eris's.
None. See above. Ares did take part in the Trojan War as a favour to Aphrodite. For his pains he got a sword cut from the Greek hero Diomedes and a stone to the head from Athena. Hercules killed his son Diomedes (a different one from the Trojan War participant) and daughter Hippolyta, Queen of the Amazons. Ares's inability to defend his own brood or avenge them just added more mockery to the God of War's failure in his chosen profession.
Why wasn't he retired?
Whilst Ares got the downgrade from the Greek myth writers, his rival Athena became in effect the Intellectual Goddess of Clever War. She got her own armour from Hephaestus (a deliberate move by Hephaestus for what Ares had done to him) and a reputation of being merciful in battle if warranted. Ares was a winner take all type of god, there would be no survivors or 'second chancers' with him.
If Ares was so useless, why didn't the Greeks retire him and demolish the temples? Perhaps that would have happened eventually but then the Romans 'avenged' the insults aimed at Ares by defeating and conquering the Greeks. The pointy headed philosophers lost out.