Why would it shake out to $1 = 1 LP?

If AA sells a plane ticket, the amount of the fare covers three costs. (1) The cost of providing the service -- transporting you and your bags (incl. support costs for ticketing, check-in, etc.). (2) The cost of the AA redeemable miles you earn. (3) The cost of the loyalty points you earn. Anything above that is AA's profit margin. The first category dwarfs the other two.

For the cost of miles earned, a base member needs to spend $5000 in economy class tickets to earn a free flight at the standard award level. At a redemption rate of 1 cent per mile, thats a $250 cost to the airline (5% of $5000). But not everyone uses their miles and the real cost for redemptions is probably less than 1 cent per mile. So we will say 4% of the ticket goes towards the miles earned.

What is the cost of a loyalty point? For many fliers who fly once or twice a year, there is no cost to AA to provide loyalty points. Even someone who earns EXP status through credit card spend alone isn't really costing AA much of anything if they fly just once or twice a year. A cost of 1% of the fare is probably an overestimate.

AA can make money if it sells 1 redeemable mile/1 Loyalty point to a third party vendor 1 cent. That means the vendor is effectively paying AA a 1% commission on its sales, so it can afford to offer $1 per mile/LP. But if the commission is higher (e.g. 25%), such as in the case for flowers, then you can offer 25 miles/loyalty points per dollar spent. Everyone is still making money, including AA. SO I would expect the varying levels to continue based on the commission the vendor is paying over to AA.