The coming Garlean invasion

[ObsidianFire]

The exact description of what is going on in Eureka is this....

Rowena
It's good to see a familiar face in these parts─particularly that o' the woman who might well be my most valued customer.

Hancock
I gather you were not expecting Krile or myself to be attending this little tête-à-tête. As you will see, however, this is a matter which concerns us all.
It all began when a vessel of the East Aldenard Trading Company happened upon an island in the Glass Ocean. A deserted island which was not recorded on our charts and, quite frankly, had no business being there.
Suffice it to say, we were surprised. Pleasantly so, in fact. An unclaimed, undeveloped island in such a location would be a boon to our trading concerns in this corner of the world.

Rowena
Kugane's bleedin' us both dry with its tariffs. Dependin' on the goods, we're paying more than ten times what we'd owe in Limsa or Ul'dah─which is already too damn much, believe you me.

Hancock
What my dear Rowena is trying to say is that having an additional port of call in this region─one more amenable to free trade─would be in the best interests of a great many parties.
Which is why, upon learning of this island, I immediately authorized an exploratory expedition. The team was large and well-funded─I spared no expense. Alas, only a handful returned.
The survivors reported “irregularities” with the island's aether, which we believe gave rise to a number of strange and monstrous beasts─beasts which set upon them not long after they arrived.
This regrettable turn of events forced us to reevaluate our assessment of the island and put our plans on hold for a time. If development was to proceed, it would require a great deal more capital than originally anticipated...

Rowena
So he came to me and mine for a handout, and I obliged. But before you scoff, know that some of my regular customers were members o' that failed expedition, and what they told me was enough to justify the expense.
Tales o' treasure, of untold wealth and riches and gods know what else. Aye, we'll have to wade through all 'em beasties, but with great risk comes great reward, as they say.

Hancock
Spoken like a born entrepreneur! Your ambition and ruthlessness are admirable, my lady. I daresay I could stand to learn a thing or two from you.
...In any event, having formed our partnership, we wish to dispatch a second joint expeditionary force to the island. That said, if we were to send just anyone, their fate is like to be the same as that of the first.

Rowena
So this time, we've a mind to send a dab hand. A veteran of a thousand thousand battles. A tried and true killer. You see where I'm goin' with this?

It's worth noting that there is literally no other ports in Hingashi foreigners can come too. And if the Samurai quests are anything to go by, that could change really quickly depending on who is in power. Having another port that isn't dependent on the Hingan government's whims would benefit not only Eorzea, but all the other countries who want to do business in the region.

There's also literally no one else who would fund this kind of thing. Eureka is a death-trap of an island to the point that Rowena asks the WoL to be the muscle for it. The city states aren't going to be interested; they've got Garlemald to worry about. Depending on where it is the Glass Ocean, Hingashi wouldn't be interested in it; it might not be close enough to their main island. Even if they were interested in it, the odds of them having people strong enough to clear Eureka is really low. The trading companies though? Not only do they have a good reason to want Eureka cleared, they also have the capital to throw at it. And the connections...

[Iscah]

The exact description of what is going on in Eureka is this....

I think it's also worth quoting the next few lines of script after Rowena and Hancock's conversation that you posted.

KRILE
While I lack your aptitude for warcraft, I will be joining the expedition as a researcher. The Scions have an interest in this island─
...How perceptive of you. You are right─this is not the sort of affair that would normally concern us. However, after speaking with the others, they have consented to my participation, on account of my personal interest...
You will forgive me if I say no more at this time. If my suspicions prove true, then I will tell you everything. I promise.

HANCOCK
Right, then. I believe that covers everything! The company ship that will deliver you to the island is waiting to receive you. You may proceed to the pier whenever you are ready to depart.

...which leaves the option to interpret our willingness to assist the Eureka expedition as purely to help Krile and the Scions, while furthering the aims of Rowena and the EATC is an unfortunate side-effect. I'd like to think we would have refused if it was just Rowena and Hancock asking us to help with a business venture.