I have worked for companies who have viewed boost as library to avoid due in part to its past reputation as a poorly managed project. I know things have changed with the project, but commercial projects who want to use boost must be aware of the source of the code contained in the library, or at least be assured that they're not going to be liable for IP or patent infringements.
Sadly, the library has this reputation and it will take a while for it to break before it sees wide use in the commercial sector. I also feel this is a reason not to recommend it blindly.
