I have to disagree here, the ready check option is meant to be a big "Hey heads up, bout to pull, get'cherself together!" So that way, if the healer doesn't ready check, then you know you probably shoudln't pull.

Party chat isnt always an option, as you have people that play on ps3/4 and don't have a keyboard handy maybe, or people on PC that might not have one close. The ready check was always valuable in WoW when I played there, and I think it's integration here is just as useful.