I suppose I'm primarily a woodturner, whose engineering work was at least initially motivated by wanting to make accessories and tooling to support the woodworking. Now it has a bit of a life of its own but that's another story.
The problem with asking questions such as "why" is like the proverbial stone throwing in glass houses since I think that many of us if we're entirely honest spend at least some of our spare time doing things that could be construed as pointless and not cost-effective. I make plenty of things that represent very poor value if I were to value my time at anything even approaching half the minimum wage, let alone the real value and they're to support another pastime that's a bit pointless too!
I think the simple answer to "why" do we do any of it is because we can and because we enjoy it.
Having said that though, and I don't make them, but pens do sell quite well as presents, especially at this time of year. Wooden boxes are my thing and as Jason says there's a limit to what you can give away but I enjoy it none the less. I haven't seen torch kits and prefer a headtorch too but suspect that they may be fun to make.
HTH
Jon