the Mnk by blaming developers and ignoring evidence that HTML5 is not even matching Construct Classic (which by Scirra's admissions is not nearly as optimized as C2) the stand-point of Scirra on this is that it's not their issue to deal with. And to a limited extent they're right, most of the problems occur on machines that simply can't run HTML5, or problems in NWJS export that Scirra has no control over.
But given the way C2/C3 are advertised as "export to all these platforms" and "nearly as fast as native" I personally feel like there's some valid arguments for Scirra to take more control over the export side of things.