Why?
The language itself is… fine. It has some bad decisions baked into it, but what language doesn’t? And it has a pretty mature security model, which is a big help for embedded devices.
And given that so many embedded devices these days are talking to cloud services — that are probably running JS, but are at least communicating via JSON — being able to share some cross-platform code or tooling can help things go quicker and/or safer.
Edit: This is probably not a route for teams that are chronically tight on memory and choose to solve that by spending hundreds of dev-hours on optimizing code rather than adding BOM cost. But for teams that could stand to increase BOM cost as long as the savings on dev-hours make up for it… it could be an option.