The difference is that the Chinese intelligence agencies abide by Chinese law and don't really pose any kind of threat to American citizens, while the American intelligence agencies engage in unconstitutional schemes (as ruled by a federal judge) to illegally spy on Americans and lie about it to both congress and the American people, murder American citizens, and can, at any moment they want, fabricate evidence to procure no-knock search warrants where a team of armed gunmen will throw flashbang grenades into the homes of journalists and political dissidents in the middle of the night before barging in with assault rifles.
And yet, for reasons that remain beyond me, many Americans remain more fearful of the former than that latter.
The consensus is usually "well the government only targets you when you probably deserve it" whereas china is spying on everyone regardless of your opinion of the actions of the current administration.
To address your last paragraph - it’s not unlikely the latter use all powers to divert attention to the former as it conceals shenanigans of the latter
Perhaps because foreign governments with a known antagonistic stance would happily sell or hand over your data in order to cause large-scale economic instability via account attacks, political instability via fostering the prosecution of minority groups (as identified by said data)... get creative. Large-scale data on your enemy's citizenry is a new weapon in the modern arsenal, and we haven't seen anyone really try to use it yet, but I suspect the results when they do will be ugly.