I deny the fact cardinal is a lower position than a patriarch. From what I've read by some EC poster here (Dc Lance?) cardinals have precedence over patriarchs on liturgy. They also have some prerogatives outside their territories patriarchs do not have. They can also chose popes what patriarch can not.
See, not really a demotion.
I've read about some propositions to make patriarchs who are not cardinal bishops equal in rank as cardinal bishops without making them cardinals but this hasn't been done yet.
Regarding liturgical precedence, I'll let Catholics correct me if I'm wrong, they probably know better than either of us, though I got my information from books by Catholic authors, not just people on the internet, however knowledgeable.
Cardinals do have certain extra-territorial prerogatives that Patriarchs don't have, but I'm not sure how many Eastern Cardinals avail themselves of those prerogatives anyway. For instance, I know Cardinals can confirm and hear confessions throughout the world (i.e., they have universal faculties), but when's the last time an Eastern Cardinal did confirmations for a Roman rite community in the Roman rite? A Roman Church penitent can approach any Catholic priest, Eastern or Western, for confession, as long as that priest has the requisite faculty to hear confessions...no one stops them from going to an Eastern priest, but it's not like Eastern priests are chasing after penitents. They have a kind of diplomatic status according to certain international conventions, but that's really a secular matter, not ecclesiastical. The extra-territorial prerogatives are more a Roman Church matter, addressing the status of Cardinals outside the Diocese of Rome, where they properly belong; they don't make sense in an Eastern context. Neither does a Cardinal's hat, I'd say.
That Cardinals elect the Pope is a relic of the past, when the clergy of Rome would elect their own Bishop. From an Eastern perspective, I'd argue that Eastern Catholics, if they're serious about "communion" rather than "subjugation", really ought not vote for the Patriarch of another Church. But if they deserve a vote for some egalitarian consideration, this could be done by a change to the law, without requiring that they also become Cardinals. But it is what it is at present. It doesn't create a lot of problems unless you think about it.
So I maintain there's a difference between what a Cardinal actually is (in principle, a cleric of the diocese of Rome) and what people think he is (a "senator" or Cabinet minister). If you consider all that "not really a demotion", so be it, but that's too simplistic, given the history, for me to take seriously. If the Catholics want to set me straight, though, they are here and so am I.