So what happened here is CSS is in a 42 degree orbit. The lower the inclination the more bonus you gain in delta-V during launch from Earth's spin. The closer your launch site is to the equator the lower your minimum inclination. You can always launch from low latitude launch sites into high inclination orbit easily (eg: the most extreme case you can launch from any launch site into a polar orbit no problem). To launch from high latitude launch site into low inclination orbit requires the launch vehicle to do a "dog leg" maneouver during launch which wastes delta-V and/or reduces maximum payload for a given rocket.
Wenchang (LM-5B and LM-7) - 20 degrees
Jiuquan (LM-2F) - 41 degrees
Baikonur - 46 degrees
Cape Canaveral - 28 degrees
So you can see Wenchang due to its advantageous location could have placed the station in a much lower inclination orbit, but in order to accommodate Shenzhou launched by LM-2F from Jiuquan they ended up putting the station in 42 degree orbit.
42 degrees isn't really that far off the 46 degrees from Baikonur, so if Russians wanted to they could do a four degree dog leg during ascent and be in the correct orbit. Depending on your launch vehicle stack though you may or may not have enough delta-V to perform this. Alternatively you might just launch into a 46 degree inclined orbit, then either use the spacecraft's engines or via some kind of orbital tug and perform an inclination change into 42 degrees. It's not an insurmountable problem mealy an annoyance.
ISS is on a 51.6 degree inclined orbit precisely to accommodate Soyuz and Proton from Baikonur, it does mean launches from Cape Canaveral to the ISS isn't as efficient as it could have been.
