The impression I got was that it was a lot slower than a 30% performance hit, but perhaps the Qualcomm CPU is that much slower? If so, it really begs the question—Why bother making a tablet-laptop thing which performs so poorly?
The tablet-laptop form factor is great, and a lot of people simply don't need high performance but do need to run some specific line of business application from 2003, so including x86 emulation makes sense.
Lackluster performance means low adoption. Low adoption means developers have no incentive to support it. Lack of developer support means little or no software will be written for the platform so performance never improves. Repeat.
And yet Electron rules cross-platform desktop development, not Qt nor wxWidgets or openstep.
Developers are fine with worse performance - even lackluster performance - if a platform or framework offers some other compelling advantage, especially _developer performance_ (i.e. it saves money).
Electron saves money because creating one-off custom UI widgets can be done easily and cheaply with just HTML+CSS+JS. While there are many things that are literally impossible with HTML+CSS+JS at-present (such as "splitting" a rendered UI, like how iOS 5 did with its notification banners and home-screen folders), but besides certain flashy effects everything is doable quickly. Whereas building a custom UI in any other platform would take days or weeks just to get a prototype done if you couldn't hack-on additions to an existing "UI component".
So your line of reason would be improved by saying:
"Lackluster performance with no other benefits means low adoption", the rest then follows.
Because those performance stats are the usual level, Apples own chips just exceed the general trend by a huge amount. The hardware is just better than Qualcomms or any other widely available ARM cpus.
The difference is that Microsoft is locked into using Qualcomm chips, which just aren't very close to Apple's performance.