I think the "app gap" isn't entirely the issue. Most "apps" are just windows to a webapp that could easily be handled over the internet without paying google or apple, and I'm noticing several workplace-related apps doing exactly that.
You look at facebook for example, and people complaining that the windows version is a terrible quality. The problem is ALL versions of facebook app for ALL OSes are terrible quality. It's a battery-draining mess that has probably resulted in more needless device returns for "battery life" than anything else! I remember a year ago mobile nations had in both android and iOS sections an article on the joys and wonders of uninstalling facebook and going from the webapp.
You look at apps for smartwatches, home automation, etc... and you find there is absolutely amazing 3rd party support for these. Run your nest and color-changing lightbulbs from your phone...or your xbox. Just speak to Cortana and she'll handle everything. I am absolutely LOVING Pebble Time Manager, bugs and all.
I think the real issue is that Microsoft has pulled back to regroup. We don't hear anything, we don't know anything, and this frustrates the fans who don't know who to blame. They think it's being ignored and avoided. Meanwhile websites like this one blog those sentiments and validate them, which only frustrates those fans more. It's like I said in another thread, Microsoft isn't happy dumping time and resources over and over just to get 3rd place... they are in it to win it.
I also know that fans are fickle, and that Nintendo fans were acting EXACTLY THE SAME as what you see here in any Nintendo-related forum before the Switch was announced. "OMG THIS IS THEIR LAST CHANCE! THEY'RE GONNA DIE! SONY IS GOING TO WIN EVERYTHING!" (Gimmie a break, Sony is bleeding cash right now...) Businesses often won't reveal info until they are ready. They want to know exactly what they can reveal to both tempt customers and avoid future confrontations. They want to give the biggest surprise so their competition has to react rather than prevent.
And you know what I think... Microsoft's been pulling some interesting and creative work involving virtual machines lately. Just look at Xbox. I think that if whatever Microsoft is up to can run win32 or win64 software, the app gap will be squished like a bug. Who cares about an "app gap" if you can just install bluestacks? Is it as efficient? No. Will it eat your battery? Probably. But google play would look kinda silly to a gamer sitting next to full access to something like Steam, even if not everything ran perfectly.