Untrue. There will be players that will yolo through areas but more often than not they will assist you if you are exploring or will point out useful items for you and hidden areas. Keep in mind they can not face bosses unless you are present to initiate the fight. You can always stick to solo and call for help when you need it.
I wouldn't advise co-oping unless you absolutely have to. in most cases, you don't really have a persistent state of co-oping in a souls game. you really have to go out of your way to play that way.
what I mean by "play online" is be connected to the world -- be connected to PSN -- so you get the various asynchronous online features -- not that you necessarily will play much co-op.
Thanks!