Michael Mace:

I think the best future for Facebook is one in which the web, including the mobile web, stays open to software-only innovation. In this world, customers choose which websites and web apps they want to use, without being forced into a particular choice by a hardware manufacturer. This would enable Facebook to run on all smartphones, keeping the company focused on expanding its network and adding new features and services to it. In other words, Facebook could keep doing what it does best, rather than pouring money into a new set of skills and gambling that it can out-compete Samsung and Apple on their home turf.

If Facebook creates its own smartphone, I think it makes that open future less likely. A Facebook phone would encourage other software companies to make proprietary phones, further closing off software openness. And it would make the other phone companies much less likely to cooperate with Facebook. Today, smartphone companies will fall all over themselves to work with Facebook. Even Apple is actively integrating Facebook with the iPhone. How long will that last once Facebook starts selling a phone? Instead of Facebook everywhere in mobile, we could end up with Facebook noplace except on the Facebook phone.

Au├čerdem beschreibt er anschaulich, warum Smartphones zu produzieren kein leicht verdientes Geld ist.