He basically became the party's skill monkey, skill expert, and general non-combat support (with a bit of in-combat support, mostly in coordination and at helping them box enemies in). Which perhaps doesn't sound like a particularly glamorous position, but apart from Ares they all appreciated his work and thought highly of him as a comrade.
Some of them were critical/dismissive of his strength in arms, but mostly in the sense of "You're not scaling well with our enemies, so don't get yourself killed." There were miscommunications, as they did not emphasize how useful he was in other areas and didn't mean to make him feel unwelcome.
Everybody thinks Ares is a bit of a git, and know that he deliberately drove Gideon off for selfish reasons.
Despite his many, many flaws, Ares is not so bad as to be an actual villain or rapist, and he is partially driven by family pressures.
Things haven't completely fallen apart without Gideon; he just made things a lot easier.
The Classes are not as benign as they might seem. Fight the Class System! Seize the means of destruction! Join the Red Party!