Like I said in my initial post, I suspect your example is precisely why they're adverse to doing challenging four man content. People will be far less likely to help less experienced players and either group with friends or in communities they know. Large Scale content lets more players participate because you only need a handful of good players do the brunt work. DRS exemplifies this perfectly. Most of the DPS players aren't necessary beyond being a body that does decent enough damage. You simply need a handful of players in specific roles (tanks on Golem/Add/MT duty, healers with reflect/buffs, someone to handle the solo duel and a few key DPS using Duelist, Elder and Utility). In reality, you only have 15-20 key players alongside your shot calling (who may be performing double duty) and everyone else is just... there. None of this is to say those players are bad just... expendable. It's that expendability the devs covet because it means greater amounts of participation and potential clears.
Put another way, they don't believe difficult four man content will garner much more interest than DRS. And the type of players interested won't be the general masses. Or more specifically, people are more likely to exclude said masses to invite their friends or FC mates.
Of course, this is all conjecture on my part. However, given how Yoshida has been decidedly against difficult four man content for years despite its frequent request and his comments of wanting veteran players to "pick up the slack for less experienced players." I don't feel I'm entirely off the mark.