Although I feel it would change the game in a fundamental way, I have come to the conclusion that an Open PvE mode should seriously be considered.
Why?
First, no single customer should be in charge of so many other customers enjoyment of a product. Mobius is the sole controller of the experience of nearly 20k players. This is something no company should let occur.
Second, again, related to Mobius, if the devs desired that their game be a large group with PvP, and all other parts lacked the ability to socialize, (basically, if you want an 'MMO experience, you have to accept PVP) then Mobius is not a work around, but is an exploit....breaking the fundamental idea that the Private modes are not supposed to be as social as Open....allowing some pressure on players to play there.
Finally, there is no place that any PvE only player can play...other than Solo...where there is not an opportunity for PvP to occur...even in Mobius, particularly as large as Mobius is. Honestly, it would not be a surprise to me to see a group of people get into Mobius and start indiscriminately killing players (it already has happened with a few groups...a larger effort could be conceived of and implemented). It is controllable....but not preventable.
To alleviate the last point, and release Mobius from being the only place for PvE, I have to say, I would like some level of PvE introduced....whether a flag system...where maybe flags are automatically removed if you commit crimes....or a separate PvE mode.....or some FDev inspired idea.