Kind of, Swift doesn't exist in isolation, there is competition to think about and unless we are speaking about iOS devs using Linux servers, there is very little business value not to chose some other technology with a stronger cross-platform support.
Yep, it sure seems like professional adoption of Swift on alternative platforms is microscopic outside of people who were already iOS/macOS developers. I don't think this is what they had in mind when Lattner somewhat-seriously talked about the "World Domination Plan" in the earlier days.
