Or do they not even explain it and just do it. Is it similar to USA where we say its to catch the "bad guys".
I guess they could argue they are "protecting" their citizens by perhaps lowering the security attack surface.
But when they do, they usually use some reason like: They must operate according to China's law.
If you dig into the law though, you will find it's very hard for an international online company to follow some of them. So often you end up with a special version for China only and/or corporate with Chinese company.
Skype did it before, it was called TOM-Skype[0], operated by TOM.com[1]. Then, TOM.com gone out of business, and TOM-Skype was discontinued.
[0] https://zh.wikipedia.org/wiki/TOM-Skype (In Chinese)
I mean I'm used to the United States where almost anything the government does the government has an answer for it (albeit probably not good answers). I guess in large part the free press sort of forces this.
So are you saying the government doesn't issue an official stance and that they just do it?
"We give you previously-unseen economic growth and prosperity. You do not ask questions."
So this falls under 'not asking questions' and 'giving growth/prosperity' when a local copy springs up in its wake. Eventually the CCP will run into the wall of reality when it comes to 'previously-unseen growth', but the market can stay irrational longer than we can stay solvent. And also, they have no qualms about just shooting people, which usually seems to give an autocratic party a few extra years if nothing else.
If you're a young and reasonably-educated Chinese person, you probably wouldn't notice that the app was taken off the store. If you did notice, you would probably see a message from the government about the app not complying with its standards. Then, you might grumble about it on the internet forums, poking a few jokes at the government, with the knowledge that this is just how tech in China currently works at the moment. Then you'd just migrate to WeChat to handle your voice calls.
I have to imagine they say something like "we are doing this to protect" etc. etc. but maybe not.
Clearly Chinese culture doesn't always amount to rolling over for the sake of social harmony, just see: Boxer Rebellion, Tiananmen Square, Communist Revolution, Xinhai Revolution, etc.
We have no way of knowing how supportive the Chinese truly are of their government if that support is given under the threat of imprisonment or loss of economic opportunities (up to and including those of family members. Under an oppressive dictatorship that persecutes freedom of speech by force, "social harmony" is really just trying to survive. In that sense, I'm sure North Korean citizens value social harmony too
Truths about things like corruption must be suppressed, because they don't look good. Thus allowing people to talk about such things is bad.