[TeMPOraL]

It's an... unusual skill to have, I'd say. Maybe it's the issue of education or culture, but I'm with GP here: in my mind, metal parts can often be repaired by hand, or an improvised replacement can be made; plastics break too easily, and you can't make new ones without a 3D printer or something.

[Freak_NL]

Yup. Same with wood and fabric. Those kind of parts or components I can replace and work with. Plastic? That's a whole different ball game due to the potentially low tolerances in terms of dimensions and the nature of the type of plastic used. With wood, metal, and fabric it is much easier to gauge the correct replacement material.

[kbenson]

I'd say education and culture might be right on the money. I'm not sure it's occurred to me to take a small block of some type of plastic and cut it to shape using knives, planes, chisels and files like someone could with wood, but now that I'm thinking about it, it seems like it might be considerable easier to work with than wood in some cases, especially with how easy it is to join two parts afterwards with some epoxy or maybe even through heat.

Additionally, it looks like you can possibly re-melt the shavings into another block (I'm not sure if specific plastic types are required).[1] That's like woodworking but being able to easily gather and compress your bits and ends and sawdust into more wood.

1: https://www.youtube.com/watch?v=34wPmcgDRmg