you're kidding right? Because I can make the non-founder curve just as "flat" by yanking up the scale on the percentage graph to 10,000%. The reason why it looks "flat" is because when you go to "count" the website scales both curves the same y-axis. I think you mean to say something like "kurtosis" - which is, if anything, obscured to the eye by the process of flattening by scaling.

And math is not a good idea when you make assumptions like normality of curves which are absolutely not normal. In this case, using the t-test to calculate a p value.

I think reification of poorly done math is a bigger problem than math by eye.