Because public relations is about relationships (obviously), not just about communications.
Tom Murphy explains the limitations of RSS, email and even the phone when it comes to relationship building. And as for video conferencing…
What’s the most effective means of communication? Without question face-to-face is the number one. You can only build limited relationships over e-mail and indeed the phone, which is why video conferencing, often the poster child before the Internet’s rise to prominence, never took off as it was supposed to. While it’s useful for brief meetings with people you already know, it’s not an effective medium for building relationships.
I recall walking away from a possible role promoting video conferencing for a big name supplier a decade or so ago. My gut instinct warned me that this technology would be more hype than substance.