Whereas prior to the CGI Tholians of Enterprise, the discussions probably went something like this:
"Well, what major thing can we throw at the crew this week?"
"How about the Tholians? We've only had one episode with them."
"How are we going to do them?"
".....You're right, let's make it the Klingons(or Romulans, or Cardassians, or Dominion, or Borg)."