If you have to wipe 5 times to learn content then all you're doing is allowing the echo buff to scale down the difficulty to your level. A good tank should always know what's coming and how to handle it. Going in blind is just lazy and a huge waste of time for everyone else in the group. Not wanting to learn through YouTube is fine but learn with people you know so everyone is prepared to spend some extra time in there. Think about it. If you were playing DPS and just waited 45 minutes to get into an instance, would you be OK spending over an hour in there while your tank learns a 20 min dungeon?