Good players but seemingly played out their butt for 4 days to win the U.S. Open. Gary Woodland? 4 career victories. Matt Fitzpatrick? 2 PGA wins and 8 Euro wins. I guess that is decent. Again my point is that these nondescript run of the mill guys rise up out of obscurity for the most part to win of all tournaments the U.S. Open.
Acting like the US Open produces a lot of obscure winners is just way off base. Again, Both Burns and Spaun are ranked within the Top 25 in the World currently - The PGA has been won something like 6 different times by players ranked outside the Top 100 at the time of play in the year they won just in the 21st Century here. The Masters has been won repeatedly by obscure low-ranked players at the time of play.... Mike Weir (2003), Trevor Immelman (2008), Angel Cabrera (2009), Charl Schwartzel (2011) and Danny Willet (2016) just in the last 25 years. Over this same period, The British Open has been won by Ben Curtis (2003) - ranked 396th in the world at the time he won (lowest ranked player at time of play to have ever won a Major by a country mile). You've also had Todd Hamilton, Paul Lawrie....... etc....
Claiming that Burns and Spaun are obscure, low-ranked players both ranked inside the Top 25 in the world is just ridiculous. They might be obscure to you, but they aren't considered at all obscure or fluky inside the Professional Golf Community.