Mainly, because it's a much better interface in every way. You've got search (that works) for Waves, multiple editing at once is done really well (with colors

Mainly, because it's a much better interface in every way. You've got search (that works) for Waves, multiple editing at once is done really well (with colors for different people), seeing who added Waves works great, seeing what people edited works great. Not to say that there aren't problems. There are tons of usability issues. But it's still the easiest way for a group of 3 people to keep each other informed of project status, etc. At least, easiest that I've tried (and admittedly, I haven't tried too many such tools.)