Hainan didn't give this route any real chance to grow. 2 a week in each direction with the odd Dublin stop over that they weren't always advising people about and at strange times is not doing the market justice.
The emotion seems to be overtaking any rational business sense in your reply. Have you got any remote idea as to the level of investment required to support the service even in its current form? If it is not working - regardless of the reason why - airlines cannot afford to lose several million (and that's the quantum we're talking about here) flying aircraft at below break-even load factors and/or yields unless they see some very clear signs of improvement on the horizon. If you want a daily Beijing service with Air China then it is going to require tens of millions to support it. [Even then, it is not bound to succeed - Qatar Airways at Cardiff being the obvious example.] If you haven't got those tens of millions to chuck at it, then you have to make do with what the market can provide on a purely commercial basis - which you then can't really complain about.