Don't know anything about consoles, but on PC it wouldn't make it a subscription model.You said get rid of solo....... Solo is the only mode you can play on console without paying for psn+ or live gold. I have a PS4 but I don't pay for psn+. I am all for an additional mode for PvE and indeed such a mode was heavily intimated in the KSer (multiple open modes with different rules). But equally some players just want to play either with just friends or a curated set of players OR on their own either through choice or necessity.
So I ain't disagreeing with your premise of an open PvE but my "bit of treasure" is just a fact of life for console folk
Also when you think it through an open PvE is not as simple as you think. Is it based on trust where damage is still done if you don't police fire or what where you fly ? In which case I would use it ... But some players would certainly troll that so FD would have to spend man power policing (accidents happen so need to separate griefers from accidents) or would there be no friendly fire and ghost ships to shop ramming (the only way to fully stop griefers) in which case I would not go near such a mode. Policing fire in a furball and whatching where i fly is part of my PvE game.
If Fdev can create a game from scratch then they can certainly make sure that be zero damage is done to players from other players, so no issue with trolls.
This game should have been either a solo only game (as it was originally intended), or should have had a PvE mode right from the start. Its not too late for them to make it so, with the 2020 update, but I am a realist and won't hold my breath.