There is a second reason however, that I am glad I only have two players. Burning Wheel is a heavy, crunchy, rules dense system. Its hard work to learn, teach, and play. Burning Wheel sits at the border between the rules heavy simulationist games that rose to popularity in the later ADnD days of the late 80s, and the New School of narrativist games, that focus on storytelling rather than numbers, that Burning Wheel is one of the fathers of. Burning Wheel has both this clever narrativist approach to defining and playing characters but it is also as number crunchy, if not more so than DnD 3.5, or GURPs, or any of the other technical systems. The book itself is full of self defined acronyms and terms that you forget if you don't play on a regular basis, and the experience, skills, and number systems all revolve around a cleverly interlocking fist full of D6's system. The influence of ADnD and WhiteWolf games is clear. Going forward in time, the idea of defining a character with a few key phrases and attaching a mechanical meaning to said phrases is central to the Fate system, and can be seen in FFG's new Star Wars Edge of the Empire game. Many Indie games such as Fiasco or Hot War also clearly owe a debt to this design.
Burning Wheel is hard work to play, it takes a good 5 minutes to create and stat a monster, and running a fight sequence or a verbal exchange can get bogged down in rules, and i don't know if i'd be that keen on running it with more than 4 players. If I want a narrativist game Dungeon World offers a simpler and more accessible, if more limited, system, or as more often than not these days, if I want a more old school gamey experience then Dungeon Crawl Classics or OSRIC will likely out compete Burning Wheel for table time. I will keep the book, its a very pretty book, and probably play it now and again after finishing this campaign but I wonder if the ever evolving RPG world has moved on. I suspect that rules light systems are the future.