For instance, I have no idea what the metrics in Figs 2 and 3 are exactly, but I can see that the inequality metric in Figure 2 has reduced itself to approximately 1970 levels and that, since 1995, the welfare metric in Figure 3 has increased by (very roughly) twice the standard deviation of the past 30 years' measurements.
Of course scale is important, but it is folly to trot out the same argument every time a graph does not include the origin. Without knowing something about the y-axis variable we cannot make this type of claim.
I don't think "the bottom of the Y-axis isn't zero" is a guaranteed bad graph, especially considering some of the horrendous graphs out there. These ones are not that bad.
Suppose we want to show changes in temperature---unless you use the Kelvin scale, showing percentage changes is going to be bogus. Showing change relative to recent volatility seems useful.