Even if I had a full scale performance in a cell phone with great docking capabilities, I probably would rather have a separate desktop computer for working. Just being able to compartmentalize "social stuff" on my phone, and "work stuff" on a desktop tends to vastly improve my performance.
To expand on it, its also a security thing. Having my phone with a network of personal contacts and my computer with more work related data means a separate of attack surface.
At this point, if you have anything worth securing, its probably a good bet that your device will get compromised in the next 5 years. Compartmentalized devices helps with that significantly, since it means only partial compromises.
