Cartel stuff won't be bound to legacy because it'll cost them profit. Why give you that mount for $15 when they can have you buy it 12 times and make $180? BoL gear hurts crafter economy if it's craftable.
You assume the cartel market is their only one source of profit. It isn't. It's not even their main source of profit, although it does exist to promote their main source of profit (subscriptions).
I'm not sure what your point about mounts has to do with making armor B2L and adaptive.
Finally, several responses to your third point:
1. We already have legacy gear which people use for alts. This would simply increase the pool of available outfits, which could
2. Increase the demand for what few crafted items aren't hideous. I might even impel them to design nicer things.
3. Your premise that SWTOR has a robust crafting economy is false. Low aesthetic appeal and utility of what can be crafted was never that high, and with the exception of a few endgame items not much is being crafted anyway.