All the Tea in China

I see Bryan is lamenting (on Twitter) the disappearance of his favourite Darjeeling tea from supermarket shelves and its replacement by the ubiquitous Earl Grey. I sympathise. And there's another tea-related mystery - the disappearance of China tea (and indeed, in Sainsbury's case, of their excellent China-Darjeeling blend).
 When I was growing up, it was routine in tearooms and hotels to be asked 'Indian or China?', the China option being a decent refreshing blend of black Chinese teas. This hasn't happened for donkey's years, and generic black 'China tea' seems to have all but disappeared, replaced by countless versions of green tea and the tarry stalwart Lapsang Souchong. Even online and in specialist shops it's quite hard to track down black China tea, especially in teabag form (yes, I know this marks me out as a philistine in these matters, but I really can't be doing with cold soggy tea-leaves). Isn't it odd that in an age when everything we buy is made in China, the one thing they aren't supplying us with is tea.