They bound it to the account so that it would transfer via cross save. This was done so those who cross save would not have to buy it 2-4 times to use cross save.

The expansion is linked to your console account, the season pass/battle pass bs is linked to your destiny account. That's why you can't share it.. It's normal in this situations, so you're getting what you want. This is just another reason why me and a lot of other ppl are saying for a long time that this y3 content model is a bs and a step back to the franchise. Same way I said after they announced that destiny will become f2p that was a bad move and could be the path to failure of the franchise. We'll see, but I don't like how the things are going atm..

Cos bungie want more money. On the plus side, you'll soon be given a list of (fake) [i]other[/i] reasons/justifications from the fanboys to choose your favourite from. Enjoy!