The company continues to grow, but the stock hasn't followed suit.Airbnb (ABNB 0.25%) has become one of the largest travel companies in the world in the relatively short time it's been around. It has changed how people travel, opening up new experiences in regions and cities that were previously hard to travel to due to lack of hotels.It has grown to be a $12 billion company, about four times its revenue when it went public four years ago. It generates a lot of cash, and it's highly profitable.However, its ...