I tend to use my phone because tapping on the screen doesn't cause as much noise as typing, the communication apps I might be using to talk to people make more sense tend to be better designed to quickly operate on phones, and it is much easier to take my phone--with the notes I was writing--with me to a speaking podium than my laptop.
That all said: you are saying it is somehow different to you if someone spends their time staring at a laptop, but not a phone? The real response that seems important here is "this is the future: phones are the new laptop"; I typed this comment and my prior comment on my phone, as I tend to do all my comments... what are you still using laptops for?
