After both the Tick and Arthur had basically been The Load for Sewer Urchin inside of the sewers during their mission in there, they're able to directly contribute to the villain's defeat. Urchin gives them a big thumbs up and says, "Nice work."
Chairface Chipendale referring all the villains that came to his party as friends. Several other villains get chocked up when he reveals he never could make any friends due to his face.
Whereas the majority of the amateur superheroes in the cartoon are superheroes out of boredom, appearances, fame, etc., The Tick and Arthur are superheroes out of the need and want to stop crime. As Arthur put it, he may be a better accountant, but that job doesn't save lives.