The parent comment isn't saying anti-China actions and suspicions by the government are xenophobic. It's instead saying more or less the opposite: that the delay in these kinds of actions is possibly down to policymakers seeing China as lesser and not worth concern.
And the US befriended China for important strategic reasons starting with Nixon. If they underestimated anything it was the ability of an authoritarian regime to retain power through such a period of economic growth. Middle classes tend to want western products and media. But the economic growth itself was a deliberate goal of US policy.
I was going to add some about at least several decades of US/Western approach being from a playbook of having the market kind of lead to liberalization on its own, and the Chinese government's ability to reap the rewards while maintaining control, but I didn't want to bloat the comment.
As for xenophobia being the opposite, I imagine the comment being referenced (now several levels above) was using -phobia in the common modern sense of including bias or prejudice and not literally fear.
