patriotism in such things as space exploration is laughable, however reasonable commercial reasons behind it are (well described in another post). seeing logic "usa reached pluto" instead of "mankind reached pluto" is a bit sad, and i don't care if it's US, China, India or Monaco spacecraft. it just feels as wrong and antiquated view of the world... but maybe typical to generic US person? (no clue really)
well if they care, you shouldn't be then surprised that this approach would go against the fur of quite a few people (safe to say more than 1000% of US population?). and since even people with different mindset, like me, find it a bit distasteful and unnecessary, not-so-positive reactions are to be expected. btw welcome to the internet, where people complain about stupid things, all the time :)