Of course Stencyl is doing better. It came first. Flash, even now in it's sunset is a robust technology, widely supported by all browsers with no kind of difference, has integrated support in gaming portals and every kind of social networks.
Stencyl took advantage of that and used it the best it could. It used everything existing and provided support for it. Users knew exactly what to expect, and flash was dominant.
You can take flash wherever you want, and run it. Support still exists and Flash will still last. In my mind, Flash IS integral to the web experience.
Construct is yet the new kid on the block and the only constraints it has are those present in HTML5. For a while, if not always, Construct will be shadowed by Stencyl.
Should we as users care? I think not.