What happened is that this isn't DS1 or 2. The gameplay is quite different, and as designed there's no point in allowing players to move completely away from each other.
Note that the camera is, by all accounts, too cramped for three and four players. If that is your complaint, you are, by my estimation completely right in feeling aggrieved. For two players, however, which is what you seem to be doing, it is perfectly fine. There's absolutely no reason in the course of gameplay to leave your co-op partner standing somewhere.
For reference, check the feedback from DS1 and 2 fans on the forums, at the time of release. Fans of the series were angry. Other people not so much.