Is it fair to automatically assume everything made in China is sub par quality?
IMO, no. Seems to me, China today is roughly where Japan was in the 60s and early 70s. "Made in Japan" rather quickly went from meaning "cheap junk" (plastic toys and flip flops) to being a standard of excellence in engineering and manufacturing. Likewise, China is producing much more than cheap T shirts and sneakers these days. Some Chinese HiFi products (especially streamers and DACs) are about as good as (or better than) anything on the market, unless you get into ultra high end stuff. Have a look at Lumin products for example. Actually, Lumin is veering into ultra high end (depending on we define that).
I don't know about Made in China loudspeakers, but wouldn't automatically assume they're inferior. Just try to verify there is decent after-sale service/support for wherever you live, Loudspeakers are challenging just by virtue of size/weight compared to rack components.