ZOS did a great job in making Battlegrounds Soloqueue only, so every Player can have a chance of getting into the Leaderboards.
Meanwhile, the PvE content leaderboards are being still owned by Trihard Guilds, against which a solo player can never hope to compete.
Get rid of grouping for PvE content and make it Dungeon Finder Solo Queue only. It is just the logical conclusion to the problem.
You did a great job with PvP content, now you just gotta pull through and make the Solo Queue deram come true.