I nod in approval when they find humans did things earlier then they previously thought, I tear my hair when they leap from that to "Must have been Space Aliens!" Yes, I know it is in the title. :^/
But they are also about the only show that is actually poking around some of these things so I watch still.
Good analysis.
As for “nodding in approval or tearing my hair”” it is the reason James Carville and Karl Rove gave up as the 21st year of the series aired. Nothing left to pull out.