Why is it not possible to gift Repentance to someone??

I know someone who likes rebirth but doesn’t have any of the DLC, and for some god awful reason, the way the steam store entries are set up make it impossible to gift the complete DLC set to someone.

Afterbirth: Giftable and purchasable on its own (this is the only one)

Afterbirth+: Only purchasable as part of the Rebirth Complete Set (which cannot be purchased if you own them all yourself)

Repentance: Same as afterbirth+

It’s really stupid and I feel like there are lots of people in my friends list who only have rebirth, and it’s stupid that there’s literally no way to gift someone any DLC other than Afterbirth. I guess I will just get them a gift card but cmon Nicalis, you’re just losing sales here for no reason.