It's worth to stress three things about the Zhengzhou-Xi'an line, the one Caixin reports as underperforming.

First, all other 300 km/h lines connect to (or are inside) one of China's three big economic centres: the Beijing area, the Yangtze River Delta (Shanghai etc.) and the Pearl River Delta (Guangzhou etc.). Through connections to these areas should represent demand of the same magnitude as connections within the Zhengzhou-Xi'an corridor. Hence, I expect a major boost for the line from the other lines to Zhengzhou. It is instructive to look at the current situation:

• There is no high-speed train from Xi'an that continues towards the east, and just one single train that continues to Beijing (along the conventional line) – this one covers a mere 1,194 km distance in 8h 48m.
  
• Since the 28 September opening of the Zhengzhou–Wuhan line, seven (mostly new) daily train services from Xi'an (out of 18) continue south along it, five of them reaching Guangzhou, one of them even Shenzhen. (The last one must be the longest scheduled service in the world that runs along successive high-speed lines: 2,221 km in 9h 15m.)

The second point is that at the time the line was opened, none of the major cities along it (Zhengzhou, Luoyang, Xi'an) had a mass transit system worth its name (unlike most of the major cities along the four other lines). But Xi'an's first metro line opened last September (ending at the high-speed station), Zhengzhou's first will open next year, and Luoyang is planning a metro, too.

_{*Lunatic*, n.
One whose delusions are out of fashion.}