Ares cares. He hides it under layers and layers of coldness and indifference, but he cares. He does not have them prove themselves to him so he can judge their skill, but so they can prove that they will survive. He knows his children are tough, but are they tough enough to survive being a demigod. He is regretful that his warlike personality was, and will always be, passed onto his kids, but he knows that, just like him, they care.
Ares has no excuse. He struggles to show emotion, but they can't know. He fears getting attached to his children, because he knows that one day, no matter what he does, they will be gone.
Ares knows that sometimes he must let his kids know he is proud of them, and he thinks he did a pretty good job with Clarisse. He knows it will never be good enough for his mother, but she has no demigod children. She only has her husband's son, her hero, Jason Grace, and his daughter, Artemis' lieutenant, whom she despises. No, Hera does not understand. Neither do Artemis, Dionysus, Apollo, Zeus, or even Demeter. Maybe Aphrodite. The only others he thinks can claim to truly love their children, are Athena, Poseidon (obviously, come on look at Uncle P's kid), and (though he is loath to admit it), his brother Hephaestus.
Hephaestus and Ares have never gotten along. Ares is war, and Hephaestus is forge. Both compete for Aphrodite, and both secretly long for their mother's approval, even her affection. However, they have the same problem: showing affection. Speaking of Hera, Ares would bet his motorcycle that was where they got their emotion problems from. Hephaestus has the excuse of being better with machines than people, which is part of the reason Ares hates him.
Ares has no excuse to tell. He is war, and war must not show emotion. War is cold, bloody, and sweaty. War never ends with happiness, even if it is your side that "won". There is no winner in war. You can pretend you won, but there are always sacrifices and death on both sides.
