General chat is infact for any usage indeed, but what you refer to as "random chatting" is no chatting but plain out spam in many cases causing the chat to rush by with 1 line replies, smiley faces done repeatedly, capsing and yelling random words to get others attention, roleplay slapping/killing/shooting/abuse another user, Or even talking about inappropriate subjects that do not belong in the public chats.
This is when the "random chatting" does not belong at all, when conversations turn into rule breaking and spam. General stars are sometimes more like general parasites since they cannot lay their paws off that chat and just has to grab others attention. It's respect less towards the other users within the map, general is a very good tool to get information and contact others, but is frequently abused.
This is no theory, it's a fact.