Here's a strawman: White people are more likely to diagnosed with autism spectrum disorders (ASD). If people with ASD are more likely to opt for CS degrees, by induction we'll have more white people in CS.
So even if they are more likely to be diagnosed - and I presume you mean White 'Men' explicitly, as Women are even less likely to be - they're also more likely to not 'sell' themselves during applications in the expected corporate way, and therefore not get the high-paying jobs.
Diversity is not just Race or skin colour, but that's easier to see (and to consciously bias).