You think the Chinese want some madman with a bunch of nukes and an unstable country on their border?
Uh, no.
Bilateral talks are a loser.
Then why do the CHinese send so much foreign aid to North Korea? The PRC has a long alliance with the DPRK, and they have been of no help in these failed six party talks.
How can you assert that bilateral talks are a loser when we have seen two years of six party talks fail?
They give NK so the country doesn't collapse. But that will happen eventually anyway... the real solution has to deal with their nuclear program.
Bilateral talks failed. Multilateral talks are in early stages and are the only chance for success.
Note that, in my opinion, the main concern is no NK having nukes- it's them helping other people get them. But, no one wants to accept NK as a nuclear state. Eventually, we may have no choice, but at the very least we need to stop proliferation beyond the current level.