Chinese state-linked hacking group 'leak'

[ArMaP]

Question 1 -
The term "Chinese state-linked" means what exactly?  Are they "hired" groups (mercenary-esque) who were simply engaged by representatives of the Chinese government?  Are they hacking groups who are somehow "loyal" to the Chinese government?  Is this sort of like how everyone who hates us in the Middle East is now reported as Iran-linked?  I only ask because I always thought of these 'hacking' groups as obtusely non-state-aligned... (except maybe for money.)

Whatever they want to mean, from being directly under control of the Chinese government to ideologically related.

Question 2 -
These vulnerabilities they identify in the software of magnificent multinational super-elite software companies... how is it that they are not 'fixed?'  Too expensive?

To fix them first they have to find them. It's possible that some of those vulnerabilities are not known by the makers, so they cannot really fix them.

One thing articles like this never mention is that the most common point of failure in any system is the human using it, "social engineering" is the most common way of attacking any system.