webOS as a grand whole is basically a zombie not worthy of dealing with to 99.9% of the mobile market, between developers, influencers, frameworks, and everyday project specifications for mobile sites. Even the common metrics decision makers use to determine which platforms to support no longer carry any information on webOS, instead lumping it in with "Other"--when those metrics even bother including "Other" anymore. webOS is thought of in the past tense. And it's not likely to change anytime soon.
Back on topic and to add to Remy X's great post above mine, Webkit supports exactly -0- of the WebAPI that Mozilla is working on to interface FirefoxOS (and its browser) to low-level hardware such as cameras, accelerometers, etc that allow individual pages you might ordinarily browse on the web to act as full-fledged apps. That's one are where webOS never thought to touch, and one that appeals to front-end developers given the crazy reach their work can have without having to deal with a catalog; they could simply bolt it onto their existing sites and services, if they wanted.
And those developers can start with their own design language from scratch, whereas Enyo is basically a tough sell without a ton of UI customization; abstraction of logic from style is something the great developers look for rather than the restriction of a pre-defined style guide. Has anyone ever seen an Enyo app on Android that used its "Holo" design language? Exactly.
Of course, there will always be a role for downloadable apps, which Mozilla is already inviting with their cross-platform Firefox app store on the Android and Firefox OS versions of their browser. (And perhaps Desktop as well; I haven't checked that one specifically.)
WebRTC might be one step in the right direction, but since Mozilla is actively working with the W3C to make WebAPI an actual open standard (in the future, as it becomes stable outside of Gecko as a production-level proof of concept), Webkit--and, by extension, webOS--will be fundamentally incompatible with it.
Remy X's post fills in the rest quite appropriately. Nothing is even remotely as easy as some non-technical people around here seem to theorize and think it is.