I don't know why they make packages BC only. Most of what they're charging is too much for any NBCer to afford anyways. I don't see why they have to have BC only items, when all they have to do is make the price too much for anyone to get...
If you do want to know, aqua:
Roblox thinks that BC only items makes people want to get BC.
From a marketing stance, that's correct and a good idea.
From a "Let's listen to our customers" stance, it's slightly off.