[Serious] Generally speaking, is philosophy a worthwhile subject of study?

[brewer]

Not really my cup of tea, nor would it be Crosby's.  He's strongly associated with pragmatism, as you probably read on the wiki.  That's part of why he thinks philosophy is a worthwhile subject of study.   As a commentator on human ecology, the ideas he advocates for could be useful to you in deciding what kind of chair to make, what to make it of, how to make it, etc.

They probably already have been.

Making that inference based on the wiki site seems like a stretch, but pat yourself on the back anyway.