nope, mass communication in guilds and general chats are common in all RPGs. they help build trusts between people. forums are ok, but they are not checked non stop, and if is something urgent, it will be read to late. reverse, PMs are ok for urgency, but is difficult to talk with everybody.
take the mutual help stuff. would someone give a legendary item to an complete unknown person, who can anytime leave and go to a stronger guild.
then, let`s say, someone wants to make a guild event, like fighting in arena, etc. without instant and mass comm, it would be difficult.
also, to make parties, would be helpful for new players to ask in a general chat for a party, then to pm like 50 people in his zone.