From what I understand the WSL team is small, with only a few people working on the kernel parts. I'm sure they honestly intend to deliver blazing performance but they're still busy delivering basic compatibility. Maybe microsoft should allocate more resources, since it is probably the cheapest way to gain developer mindshare.

I do node development on windows, but not in WSL. I would advise doing as much as you can with native built software and only using WSL to fill the gaps.