You should review the whole scenario, i110 gear was only attainable by raiders for a whole major patch until they allowed non-raiders to get upgraded soldiery, but HA is still only attainable by raiders - you still have exclusive rewards, is that not enough? Why focus so much on ilvl when not even first coil had higher ilvl gear than non-raid gear? Don't you think perhaps they always intended to mainstream soldiery gear, just like they did with myth gear, which again was same ilvl as first coil gear?
Raiding isn't only about ilvl or loot, and even then, second coil loot is still relevant, you are giving too much importance to ilvl.
"Lower difficulty" is not equal to "everything is handed to them." - repeat that over and over until it sinks in.
Non-raiding players don't get raid gear, there's no other way to obtain High Allagan outside Second Coil.
Raiding players also got ST, hunts and new dungeons, last time I checked raiders are not excluded from that content, and hell that I see a lot of raiders hunting or in ST.
Your third point... So you want raiding to be exclusive just because you don't have enough attention? How would make raids less exclusive affect that?
And note that should they add another mid-core (not casual) mode for raids, don't you think they would change how vertical progression works? (as in, you wouldn't see something like what happened with hunts, because said gear would be added to a mid-core raid mode instead)
Actually using myth and soldiery as examples, if they went with this raiding scheme from the beginning they could have implemented myth gear as "normal coil" rewards and allagan as "hard coil" rewards, keeping darklight as the "currency gear", then for 2.2 soldiery gear would be the "currency gear", normal second coil would be upgraded soldiery and hard coil would be high allagan.
the +5 ilvl weapon would still be locked behind hard coil, having BiS gear would be exclusive for hard coil players and everyone has something to work towards, unlike now that there's only either casual or hard content, not mid content.