I'm sorry, what? The city that hosts the Christopher C. Kraft Jr. Mission Control Center is not a science and technology hub? There is science and technology outside of social media apps and internet ad surveillance tech.
Yes, it's not a particularly important hub in the US. Boston, SF, and countless other cities are more important hubs. Having one space mission control center does not make a city into the foremost American science and technology hub.
The Trump administration decided to close down one Chinese consulate as a political message. They probably chose Houston because closing the consulate there is less disruptive than closing, say, the NY consulate. When the Chinese retaliated, they also chose a relatively unimportant US consulate to close.
Practically every consulate and embassy around the world is crawling with spies. "Diplomatic cover" is a standard way of sending spies to a foreign country. That's not why the US would close down a foreign embassy.
The closure of the Chinese embassy, with a big announcement and almost no forewarning, was meant as a political statement. It came in the middle of an escalating trade war, initiated by the Trump administration.
The post facto rationalizations about the Houston embassy being some extraordinary hotbed of espionage were absurd on their face, and I'm surprised by the level of naiveté in this thread towards these sorts of official government explanations for what are obviously political moves.