As always: there is nothing inherently wrong about either plastics or carbon fuels. The problem is in using it in incorrect situations. Plastics are perfect for transporting an preserving foodstuffs in. Cheeses, meats, etc all have significantly longer shelf-lives because they are placed in plastics in a protective atmosphere. It is things like plastic bottle-caps, plastic straws, and other (generally small) disposable plastic tools that find their way into nature and wreak havoc.

Similarly for carbon fuels: these can have extremely high energy density coefficients, and are usable on a global scale. I would still prefer a move away from them and into Nuclear, but for some situations, having a small canister of fuel and a tool to convert that into mechanical action is extremely useful. Chainsaws for instance.

Also: I don't know what the tolerances for this material are, but they might be interesting for use in space?