I really want to emphasize that heirloom. By its very existence, whales are already in on this regardless of what they do, since it's a guaranteed way to get an item that otherwise has a pity counter of 500 loot boxes. It's an endgame to the spending of this event, which is not common in games like this to begin with.
With that in mind—Respawn/EA would likely make more money selling these skins a la carte anyway. At their usual high price of $18 per skin they would grab a lot of people who just want one single skin. The alternative is the people who would buy one skin now need to buy atleast two of the loot boxes, and it still doesn't come out to as much. The thing is—this STILL gets the whales. They still want that heirloom, and would just buy all the skins anyway. Only now it's a lot more expensive for them.
Let's even imagine they were more generous than usual and made the epic items $5 each, legendaries $10. 12 of each means $120 on legendaries, $60 on epics, $35 for the axe. $215, whereas currently all the loot boxes + axe equal $203. Whales end up spending more, and I highly doubt they would even make the prices that low. They could make the two quests that currently give boxes give a voucher instead. One voucher for an epic, or two for a legendary, that way you get one free legendary or two free epics. Still ends up being more expensive than what it is now. This begs the question...
What is gained from this current system? The people who want one skin but can't directly buy it enter a lottery system. Those people are manipulated and tempted to be pushed into trying to get a few boxes and getting the one item they want, and if they don't, it's a sunk cost fallacy for them. People that might have just spent for one skin now end up spending over.
That is literally the only thing gained from this. Again, whales WILL get that heirloom and could actually have been milked a lot more. This system only gains from the people teetering on the edge already. The fact that this IS how they did things is telling enough, as there must be a whole lot of people that end up being pushed to biting on this where it exceeds some internal number, even at the cost of blatantly pissing off the userbase. That's scummy as absolute fuck.