Remember 5.0 AST? Its healing potencies were so weak it couldn't do its job for normal content, not without a really good tank and coordination. There's a reason come 5.05 they had a page long list of changes, most of which were potency changes.
I'd rather just have something to do in downtime then them try and get rid of it. This game is meant for more casual players, making it harder would go against a huge portion of the player base. Having more DPS buttons to press isn't going to change the playstyle of players that already spend most of their time healing when they should, and it gives the better players something to do.