Sometimes it baffles me how quickly people jump in on discussions on this forum a soon as open/solo is mentioned even though they don't seem to care a great deal about PP in general. Is there some kind of notification for those threads?
Imo it has been determined a long time ago that there is a problem. Sandro didn't pull the grenade without reason back then:
If you want recent examples, right now there is a Grom expansion going on Hudson doesn't like. So we send people to oppose it. Our people met Grom's people (and some Imps supporting them), both sides had losses which results in loss of merits and insurance costs. Both groups could push the expansion progress or opposition completely undeterred at peak efficiency by just winging up in a private group of their chosing instead.
This is not limited to combat activities, if you are a PP hauler you might want to use a max tonnage shieldless build. Take this
Alliance Cutter as an example. Now if you know what you are doing this will work against NPCs, but if a competent PVPer engages you you'll be probably ripped to pieces. Such builds may even work in open for a power that doesn't have enemies but I'd certainly not dare to take something like that to Nanomam.
A multiplier for open will probably never be implemented at this point (sadly) and there are other problems like bad instancing and no shared servers with the console versions. I do believe that more people playing PP in open would be a good thing for the mode in general (and if you want to argue with the low player numbers in PP, FDev did their part with making the mode unappealing to many in the first place and driving out many dedicated PPers by lack of innovation, long wait time for bug fixes or even introducing new and partially devastating PP bugs along the way).