Vacuum is bad at heat transfer, sure. But mechanical parts of the space station can be as hot as 120C (250F) and as cold as -150C (-250F), so I'm pretty sure y

Vacuum is bad at heat transfer, sure. But mechanical parts of the space station can be as hot as 120C (250F) and as cold as -150C (-250F), so I'm pretty sure you do want thermal insulation :-)