Think about all the refunds that frontier would have to issue to people who have bought lifetime expansion passes or backed the game specifically to partake in open play... it would cost them millions to remove it.
I've been playing elite since 1991 (Archimedes version) and am a backer of ED... but I understand that things move on, the games market is a different beast these days and I accept that.
I would be asking for the £180 I've spent on ED to be refunded if they removed open play, and I'm sure lots of others would too.
For a start, the lifetime pass is to have access to the game and its content + all future content.
Solo has full access to the game + content. Groups have full access to the game and its content.
So the removal of Open to make the game an even playing field for PvP'er and PvE'ers would not cost them a penny in refunds, as the Lifetime has nothing to do with the modes.
And you can ask for a refund all you like, if you bought the game for forced PvP then you bought the wrong game for the wrong reasons.
Right from the Kickstarter it was made clear that people have the choice to PvP or not. So your request would fall flat on its face, as the modes are just a way to choose who to play with, which you can do via Groups.
Open = Group set to accept all join requests.
Solo = Group set to decline all join requests.
Groups = Group set to player admin controls and not an auto accept / decline.
All Solo and Open are, are auto controls for the matchmaker. Both could be removed and not impact the game play.