As someone who's similarly red-green colorblind, I'd say it's far more likely to be related to the amount of time he's spent reading and writing code on monochrome displays, perhaps coupled with market trends that tended to associate color with cheap/mainstream/gaming hardware vs. monochrome with expensive/professional/engineering hardware. For several reasons, there was a major trade-off between color and contrast/sharpness/resolution on most hardware until the mid-90s or so, and there was a tendency for engineering-oriented systems to embrace monochrome to get the highest contrast and resolution.
I don’t think that’s it. I used syntax highlighting for nearly 20 years then stopped a decade ago and don’t miss it at all. So I had every reason to want to use it but now I don’t even want it.
