It’s biased to think that average Chinese soldier wouldn’t have the same loyalty or patriotic zeal as western soldiers. It all goes back to the institutionalized indoctrination long before boot camp, and indoctrination is something regimes like China do very well from the beginning.
The corrupt soldiers and officers are a real problem and will cost lives, but being a lone son/daughter also puts an enormous pressure on them as the sole protector of their family and country. When the PLA does eventually fight a war. The average Chinese soldier will fight with the same ferocity and motivations. That soldiers of good and bad regimes have fought with for ages.
I do also agree with you that high casualties will turn public opinion against a war; in any scenario except an invasion of the homeland. Although that’s also true of any modern country with the scope the media has to get the grim reality of war to the publics attention.