I'm the RRCA rep for N. FL. I can tell you that it varies from club to club. The club in my city has stated outwardly an interest in having their courses USATF-certified, but they do not aggressively, much less mildly, pursue the endeavor. On the other hand, the clubs immediately to the east and west (one not in my region/state) have nearly all of their courses measured and certified.
We (RRCA) strongly-encourage certified course use, and require it for ALL of our championship races.
I've worked with a very proactive approach in the past, "encouraging" certification efforts, but after one five-year stint (and a five-year hiatus) I'm now waiting for clubs (at least in my immediate area) to ask - either 'why don't we get championship events?' or 'how can we get our course/s certified?' It's kind of a tip of the iceberg on the course quality issue - I've measured courses for certification and had the race director set up the course whatever d*mned way they please - and had people complain that the course was "not accurate according to their Garmin." Providing the RD every piece of material to make their race as quality as possible is of no use if they fail to listen.
*steps off soapbox*