The only way they can truly stop it is to come up with better ideas that organically pull people into open, or leave those in open feeling less bad about it and/or having a better chance of meeting players organically. And have it implemented by FDev. Totally doable...............
Well, FDev have already done that on numerous occasions. It makes not the slightest bit of difference to the arguments.
Over half of all player activity is in PC Open. That's been true for ages and hasn't changed. The total amount of player activity has
much more than doubled since suggestions about making more attractive started coming through - the busiest systems now are about five times busier than they were in 1.0, the quieter systems are two-to-three times busier ... and that's not counting the big spike in activity from all the Epic free accounts (which has approximately doubled activity compared with six months ago).
So, if in 1.0 Frontier had only had Open, there would have been about 50% more players in Open [1]. Now, there are >200% more players in Open than back then. I see players in Open daily unless I'm poking around really obscure systems, while when I started flying around in version 1.1 I could go for weeks without seeing anyone.
Has this massive increase in the number of players in Open made any difference to these arguments over the last six years? Not in the slightest.
Would encouraging another few percent of players into Open make any difference? Well, since activity is ~30% higher at weekends compared with weekdays, and we're not at the stage where people are saying "Open is great at weekends, but we really need an incentive for people to play in Open during the week too", obviously not.
When Odyssey launches, assuming that it's not a total disaster, there'll be at least a temporary boost in player activity as everyone checks out the new stuff. Almost certainly, this will mean that the number of people in Open post-launch is greater than the total number of people in all modes right now. Will this stop threads like these? Of course not.
The only way they could actually make Open feel inhabited would be to significantly shrink the size of the bubble, to concentrate the same number of players into a much smaller number of systems - have the Thargoids set 90% of the bubble on fire and completely destroy it, then what's left would feel quite busy. But there are other good reasons not to do that.
[1] Falsely assuming here that everyone continued to play under those terms, of course, so this is a theoretical best case.