When they deliver less is when things become unacceptable.
I'll go out on a limb to venture you'll find there is something "unacceptable" with any offering on the market, now or in the near future, on its own. My point is that it's a good thing for every individual consumer to know their requirements well, and to see when and where each candidate solution fails to meet one or more of the requirements, so that everyone can select a compromise (because total satisfaction is not on offer) that they can live with for the their out-of-pocket expenses. Not having a choice between imperfect options is a bad thing, even if having the perfect solution option is not ever going to be available for selection.
I hope Garmin does at least just enough to retain its advantage in the market and remain a strong competitor.
I think nobody expects a perfect solution, but the current app for Windows 10 Mobile has several issues that the ones for Android and iPhone do not have. I am sure not all of them are related to Garmin, but most of them are in my opinion. And I think a customer who bought a Garmin device believing that it works fine with Windows Phone can expect these issues to be fixed. Also the fact that Garmin is not communicating anything about the plan how they want to go about it makes it difficult for us users to still believe in a working device.