I know guys in the VT/HTs fly their faces off, but lets not pretend that the FRS/WTI guys, or anyone for that matter, aren't working just as hard and have all sorts of free time for a masters, JPME, or personal stuff.
Based on what I've seen in FRS IP's logbooks compared to TRACOM IP's logbooks, coupled with the activity I've seen on a RAG flightline on a Monday or Friday, my perspective is that the TRACOM guys are working/flying much more consistently than RAG guys. That's not to say that the FRS guys aren't doing the job they need to be doing, it's just a job with a different schedule than the TRACOM (6-7 days a week, 10-12 hour days, depending on VT/HT).
All that said, Brett's spot on. The standard hasn't changed, it's the selection rates. And it's not just DH, it's Navy wide. I had an ADAN that was awesome and one of only 3 AD wrench-turners, but she can't advance because of advancement rates (0%). It's just the way of things right now.