I suppose at first they come here because they somewhere read about the fascination of a player created meaningful market, that they want to experience and make use of.
Then they usually show a lack of adaptation skills in gank avoidance or stubbornness that makes them believe they need to mine as a single player in lowsec due to the better ores or something along that line that leads them to demand this PVE server.
However a market on that PVE server would be meaningless again. You could just play a standalone game instead. Also PLEX would not be possible on this PVE server without a player driven economy and without real isk sinks and only faucets.
Meanwhile, fully PvE games sell tokens the same as PLEX. Converting current EvE to PvE only would only require upping the difficulty of existing PvE content, and then making more. Ships still need to be replaced when NPC’s blow them up. Keeping in mind also the majority of the people playing this game have barely enough sentience to qualify as NPC’s themselves while buying into the hype that “Playing EvE equals having to be super smart” to make your e-peens grow. You can literally be replaced by an even moderately advanced AI algorithym. I’m sorry, but you really have no clue.
No one is preventing you to get filthy space rich by only doing PVE in EVE already. Only your inability to learn the game and appropriately react to the circumstance is holding you back.