They offer their own version to gold card holders - the SSA (Supplementary Silver Account) and KA (Kid's Account).
With these, kids under 12 can also join Flying Club and all KA miles go into the gold card holder's account. For the SSA, the gold holder can nominate someone at the same address to receive a silver card, and while they earn their own mileage in their own right, the gold holder can spend miles from their account too.
Of course, the fact that you can pool miles from more than one account to pay for a reward means I'm not sure what you're missing from not having the BA setup. Granted, if the reward doesn't split into neat, big, chunks when halved then the BA scheme has some benefits (say you needed an extra 12,499 miles or something like that) but I don't see what the huge deal is with not offering it...
With these, kids under 12 can also join Flying Club and all KA miles go into the gold card holder's account. For the SSA, the gold holder can nominate someone at the same address to receive a silver card, and while they earn their own mileage in their own right, the gold holder can spend miles from their account too.
Of course, the fact that you can pool miles from more than one account to pay for a reward means I'm not sure what you're missing from not having the BA setup. Granted, if the reward doesn't split into neat, big, chunks when halved then the BA scheme has some benefits (say you needed an extra 12,499 miles or something like that) but I don't see what the huge deal is with not offering it...