While it is true that delays and cancellations happen everywhere, what makes flying in China unique (as compared to the US, for example), is the reacommodation process. Simply put, sitting in Hongqiao for 4+ hours watching flights to Beijing go out with empty seats while MU insists that your 8a flight is leaving "soon" is quite frustrating. Want to switch to a CA flight? Sure, no problem, just head back out into the lobby and buy a ticket. Of course, since you're not the only person who entertained this idea, there is a decent chance the CA flight will sell out and your original flight will leave during the 40 minutes you spend at the ticket window, the check-in counter, and clearing security again. At the point, you're back to square 1 and will be lucky to escape the airport before sundown.

As previously noted, ctrip can remove some of the agony from this drill (e.g. they can call CA in order to attempt to figure out if their flight is really on time, refund your MU ticket, and credit the remaining value towards the purchase of the CA ticket), but even then, the process is nowhere near as simple as Delta arranging for United to print a boarding pass for you as you stroll on over to the United gate.