Some people simply enjoy the concept of writing more than speaking out their roleplay. There's nothing wrong with that preference, and nebulous -- much like a large variety of other roleplaying communities that exist -- is founded on that preference. Just because it's not a community-wide preference here doesn't mean that people are "scared of" the concept. If you like intermingling voice acting into your day-to-day roleplaying, be my guest; not everyone shares that mindset, though, and even fewer people will feel comfortable roleplaying the kinds of characters they ordinarily would be playing if they were forced to communicate over a voice chat.