Just a thought, why don't Scirra and the community go together and create a native C-something / Vulkan or OpenGL translator/export controller together with Nintendos SDK? Sure external plugins will not work as long as they are not converted, and it would be a community driven effort. (this seems harder to do with C3 since the code is more closed off)
I have a lot of people around me with Switch Dev kits. (My friend Pedro, Bad North etc) it's not very hard getting hold of one as long as you have a quality game to showcase for Nintendo.
I think there's one big caveat with web framework, and why Nintendo is being restrictive about it, is security. Looking back at the vita and other devices, the browser has been the main target of bypassing security by transferring payloads onto the device.
As a power user I love Construct due to its simplicity, fast load times, and resource effective way to handling 2D games. (Unity and Unreal are just too heavy for 2D games, and game maker is a joke to be honest)
I can understand that it is not in Scirras interest to openly share your code or business, but finding ways to work together could help C3 excel as a product.