Yes they are good at amassing people to build infrastructural projects. But that is very different than having to convince people. The regime is hard-coded to do things with brute force.
99.9999% of comments you'll find online are highly critical of China. The most upvoted submissions on Reddit and HN are often those critical of China. Most Americans (60% last time I checked) already have a negative view of China and their knee-jerk reaction is to support anything or anyone who speaks out against the CCP.
Does anyone really think 17 bots on Twitter tweeting messages in Chinese is going to change this?
Try 17 thousand or 17 million bots, Tweeting in English.
This is also only a small fraction of what they are actually doing. If you take a look at many new movies coming out in the US, many are financed by a Chinese company.
They have also started buying major stakes in media companies, like Reddit.
The strange thing about the Hong Kong protests is that I can't seem to find any balanced coverage of it and I almost saw no coverage of it here on major US television networks.
And now they've got Reddit covered with /r/Sino but I'm unsure if that's new or not.