I don't want "convergence" between my devices. Why would anyone?
My phone is used for wildly different tasks than my laptop, which is used for mostly different tasks from my desktop. Any form of convergence is going to hurt at least one of the workflows involved.
I want my phone software to be as lightweight/minimalistic as possible so my phone's battery can last, for example. A desktop doesn't have to care about that at all.
Just make the best phone software, or PC software, you can, don't half-ass both.
If convergence means that I have to put up UI like Gnome 3, then please don't coverge.