I think one of the reason why coil has such a lock out is because they want to make it some form of recognition of skill?

I recall in one of the live letters, Yoshida admitted that he designed BC in a way that he only expected the top 5% of the player base being able to clear it - and it was indeed that difficult: BG was the only team that cleared T5 before the twister nerf and even to date, I think the % of players who cleared T5 remains a very minority.

Given this and that it's a locked out content, the loots itself is like some form of "trophy" for those players who are always asking for some forms of trophies. Before people even clear T5, any T4 loot that players owned are like some big achievement trophies and people are like "hey look at my T4 boots" to "show off" that they earned them via skills (since you can't depend on Primals, they are being sold all over the place).

And the recent patch 2.16 they have added stuff like Paragon Gown, another trophy item to show that you have lots of times to spare for the game and cleared 3,000 FATEs.

Yup, trophy gears they are meant to be.