I actually find it very convenient and use it like this (touchscreen shutter activation needs to be off):
- touch the screen where I want to focus (right thumb)
- press the '*' button to focus (with the right thumb which is already positioned close to the button)
I would have loved the EOS-M touchscreen and its touch-to-focus feature on my Sony A7R. I would have gladly traded away the Sony EVF for the touchscreen which makes it 10x faster to move the AF point than A7R's ludicrous two-dial system. Yes, I still can't stand EVF's.