> First, my impression is that Microsoft Surface hardware is, too, heavily advertised in developer forums and social media

I use a Lenovo Yoga X1 2 in 1. Using the laptop form factor, linux works great(as I had expected). However, using as a 2 in 1, it is not a good polished experience.

> What does it mean to have touch on a software developer system?

It means when I purchase my own personal system(which I do intermittent dev on), I can buy a multi purpose device which replaces the need for me to buy both a laptop & a tablet.