This isn't totally true. Both the US and Germany - which both have strong trading links with China - do bring up human rights issues with China.
If pressure on and public comments about China made no difference to them at all then why do they get so upset about it?
China (both the governmental level and amongst the growing middle-class - who are becoming increasingly international in their overlook) has aspirations towards taking a bigger role in the world, politically, diplomatically and culturally - it does actually want to be admired and respected and have 'status' over-and-above purely economic or wealth-related concerns.
China also wants access the best technology, the richest markets and the most profitable and forward-facing investments, which mean it does have to deal with the main OECD countries - it can't simply be as much of an arsehole as it wants and just 'shop around' - unless it wants to end up dealing with a bunch of second-rate governments, companies, investments etc.
As for 'just wanting to feel better' - I'd rather be guided by what the citizens of China have to say about how we can help them - this while obviously includes higher-profile people like the students in Hong Kong, campaigners in - or exiled from - Tibet, other groups with allies in the west (eg christian house churches) or slightly less high profile people like the Ilham Tohti (an Uighar academic currently serving a life sentence for 'thought crimes')
Ilham Tohti - Wikipedia, the free encyclopedia it also includes paying attention to the *vast* number of ordinary Chinese people who take part in local protests, for example in rural areas over their farm land being taken from them, in urban areas about working conditions, food quality, and air and water pollution and paying attention to massive issues of inequality such as the permit system which bars internal migrants from free schooling or health care in the cities where they live and work.