If you're trying to imply that moving away from completely open and unrestricted pvp is the cause of bad player retention, that's easily objected to by the history of MO1.
The game is not "dying" because of a lack of pvp content, players are leaving the game for other reasons which they are extremely vocal about in the steam reviews. People aren't happy with the state of the servers throughout launch, or the lenience and lack of perceived punishment for exploiters and bad actors, as well as one of the top complaints being the exact opposite of what you want. People aren't happy with being killed all the time.
Of course, that last one is more a case of the wrong target audience attempting to play the game without the correct expectations and being disappointed. Although, it could be argued that - being a sandbox and all - there is absolutely nothing forcing anyone to attack anyone else, and it just so happens that we have a large condensed portion of the population who wants to do that.
If we were to lose all our players tomorrow and replace them with people are more civil minded and enjoy player interaction more than just killing people, we wouldn't be getting those negative steam review complaints en mass about it.
This is to say, as a sandbox it's the current player base that determines the state of the game in this particular regard, not the game itself.
In recent events, the steam store page text has been changed, likely in attempt to attract a different player demographic that isn't simply focused on only pvp. This however will indeed need to be accompanied by additions of content that caters to those players, but it is a step in the right direction in my opinion.
