This was the period (about 2010 to 2018 when the issue of winning nationals versus body of work came into focus. Previous to that, the problem hardly ever arose (well, maybe Janet Lynn Nowicki versus Julie Lynn Holmes in the early 70s

) For the most part, the best skaters won nationals and the skaters who won nationals were the best.
I am certainly not privy to USFS insiders' thinking, but in terms of what was publicly announced, two factors converged. First USFS began to believe that the USA was disadvantaged by their selection process vis-a-vis other federations who were more active in manipulating things to their favor.
The second factor was that there was some sort of friction between USFS and the USIOC. A new head of legal affairs for USFS was hired and he pushed the point that according to the IOC charter, the national IOCs have jurisdiction over all Olympic qualifying events. If U.S. Nationals was the sole qualifying event for selection to the Olympic team, them legally speaking the USIOC could take over the event and kick the USFSA out of its own national championship.. This seems far fetched, but the situation had been percolating ecver since the 2002 Salt Lake City Olympics where the whole USIOC got in hot water over scandals involving bribery in the site selection bidding, awarding sweetheart contracts to construction companies owned by USIOC members' brothers-ib-law, etc.
By and large, fans and the general public did not pay much attention until 2018 when Ashley Wagner finished 4th at Nationals but was selected for the Olympics over third-place finisher Mirai Nagasu. I believe that a couple of factors played into the subsequent uproar. One was that the TV commentators led viewers to believe that the old 1-2-3 go to the Olympic,s 4-5-6 go to Four Continents was still in force. The second was that Mirai was a super-popular fan favorite while Ashley had both detractors and supporters). Plus, Mirai was the feel-good comeback kid storybook heroine.
Ever since then, TV commentators have been carefully schooled to say on the air that selectopn to war;d and Olympic teams are decided by a process that takes into account many factors.