While I absolutely agree with you, it seems far more likely that native implementations by Apple, Google and Microsoft will dominate the market. Windows Hello is a great early example of this.
SoftU2F was designed fully conscious of this. It was largely developed to help push forward the idea of a software based token with every hope that, over time, native browser and operating system implementations push things fully into the mainstream.
I hope they do. Wouldn't that be incredible? Having _native_ U2F/UAF built right into the browser.
The hard part is that there's another more subtle chicken and egg problem when it comes to software implementations and consumer HSM. Google/Apple/Microsoft will likely only really push forward native implementations when there is enough market share for consumer hardware having HSM's built in to make it worth it with feasible fallback options.