Respectfully, that is easy for you to say since Disney currently honors your preferred method of information exchange. Your preference happens to be in line with the one they use. *MY* preference is summarily ignored by the company.
I am a webmaster who handles all of my negotiations via email. In fact, I have to go back to 2007 to remember a signed agreement that was not largely discussed in this manner.
Even if this had not been my preferred form of contact prior to then, I had to watch two years ago as people willingly perjured themselves in order to deny the truth about a fire in my home. Everyone had acknowledged the events the day of the fire when the firemen were still at the building. Once people lawyered up, however, it was remarkable how much those (thankfully) documented events became questioned, though. Honest firemen saved us twice in this regard.
Still, that was a teaching moment for me. I recognized that anyone who uses the phone but will not leave a paper trail is reserving the right to lie shamelessly later in the process.
With this business decision,
DVC immediately troubled me as a potential customer. With 450k people, they are not going to lose any sleep over it but it was still a frustration for me.