If a person contacts me and asks a question or says something that requires a fuller response, am I then meant to replay "sorry, this isn't the medium for that"

If a person contacts me and asks a question or says something that requires a fuller response, am I then meant to replay "sorry, this isn't the medium for that"? Or should developers and companies start putting more effort into good UX? Twitter is another one, the desktop version of Twitter serves a mobile version of Twitter; a timeline that is less than a third of the width of the screen I'm now using. Now, I realise that the brevity of the messages means they could appear strange looking if stretched accross the page, but as Twitter expands to include more than simple text media, the UI needs to adapt. Twitter appears quite silly on a desktop as of today (imo) and doesn't even make good use of the Bootstrap 12 column layout.