As someone with a schizoid personality, I concur with these statements.
Interacting with people IRL is both mentally and physically draining for many introverted people. We need time alone in our head to recharge. It is very tedious to focus on a single person while they are talking. We'd be the first to sign up for voluntary solitary confinement. (ok, that may just be me)
And, yes, I have texted a person in the same room as well. Hell, skype is my main communication with coworkers even when they are sitting 3 feet from me.