I'd like to point out that it takes about the same amount of effort to earn both gear. Really should be just equal. As some have trouble making static group to farm coil and some have issue of determination of grinding dungeons every week. Either way given time both content would become easily farmable because once a group becomes over-geared for those end game content it'll become obsolete.

More over-geared people = more pugs making it through either type of content.
If they limit to being coil as the only option to the next tier, they'll just bottle neck players to farm coils every week instead of doing other content that right now rarely anyone do.