People like Passepartout for a variety of reasons. Mainly, he has so many likable traits that it is next to impossible not to like him. Even traits that might be slightly annoying tend to make him more likable. For example, Passepartout tends to emotionally react first before logically thinking about the situation. For instance, when he learns that the railroad isn't complete, he freaks out so quickly that he nearly punches the man delivering the news. The fact that Passepartout is so emotional and easy to read makes him likable. There's no real mystery to him. He is up for whatever Fogg throws his way, and Passepartout throws his entire self into making sure that he and Fogg are successful. Coinciding with that is the fact that Passepartout isn't afraid of trying things. He might mess up, but at least he tried, and Passepartout is always the type of person to apologize when he's in the wrong. He's loyal, trustworthy, and kind. Passepartout is also brave as demonstrated by his willingness to rescue Aouda. He's also incredibly gullible which also makes him well liked by those people looking to take advantage of him.