Its not the numbers that are the issue, its the agendas they have and the ever shrinking space they co-exist in. A single player can wreck a small system easily, and prolonged conflicts can get messy. Its very hard these days to not see more agenda driven play- for example in my time in Utopia I helped flip every system to favourable- thats going through about 500 systems and making sure each one is right. That massive area has to be policed and all PMFs and rando traffic kept in check.The number of pmfs did increase. What about the number of concurrent players? Is there more people playing now than 4 years ago? The simple popping up of PMFs doesn't tell much about activity. As does assuming they are all active. It's not like everybody is like the heroic Communists who'd adopt and push any red faction and diligently destroy the unwholesome occurence of Imperial influence down to the root.
And then you have solo players who may or may not do any BGS work and rather opt out of MP shenanigans. It's not like each of them cheeses the system to be untouchable 5th coloscopist.