Can someone explain to me why Legacy to New World is a bad idea?

Only thing I can think of is gil. But wouldn't the cap remedy that?

OK so you can buy expensive items with gil over the cap and resell. What's to stop others going from New to New doing the same? Why not impose some sort of cap on that what will transfer to only able to transfer Ex items? That way the AF, Primal Weapons and other like items will transfer. At least it's giving Legacy an option.