So naughty Bob logs out... and logs back in solo. Whew! He flies out of the station, and to the next system, whereupon he logs out again, and logs back in Open.
First, why? Why is Bob logging in and out of open in his T7? What advantage is there for Bob to fly his T7 in open? Personally, I think you've misjudged Bob. I doubt he'll log his T7 back into open, because he'll just be forced back into group or solo when he sees another threat. See, Bob never planned to present himself as pirate content. That is what NPC's are for.
No, the real Bob is much smarter than any of this. Bob has a secret pvp fetish he sates by flying his vulture in conflict zones in open, but give Bob a little credit: He was never going to fly that T7 in open. Bob has also thought a lot about how he'd play if mode switching was removed, and has come to the following conclusions:
If there are separate saves, Bob has decided that Mobius offers enough pvp in the conflict zones to satisfy him, so he's saying goodbye to open forever.
If there is a cooldown timer, Bob has decided to just fly his T9 (he upgraded) in solo a few hours a week, and only logs into open on the weekends to play in the combat zones. Unfortunately for FD, Bob couldn't fly his T9 on Monday because he still had 24 hours left on his 48 hour cooldown, so on a whim he picked up a game on a Steam sale, got sucked in, and FD never heard from him again.
But enough about Bob...
The real issue here is that in open everyone (that's a soft everyone meaning an overwhelming majority) wants to be the pirate or the bounty hunter, and no one (again soft) wants to be the underdefended trader. I'm sure that's even more pronounced now that profits from combat have been buffed. Only a few diehard MMO types are going to fly T9's in open, and that's just a fact.