Why would you select against people with poor vision?
The green seems a bit harsh, yes.
But all in all it is a good page for people with poor vision.
No low-contrast and no white background, which are both considered bad on screens.
Yes, the white on black is fine. I checked the #8a7ae2 purple (http://webaim.org/resources/contrastchecker/) and, surprisingly, it passes WCAG AAA guidelines. I say "surprisingly" because it hurts my eyes. I think jumping between the alternating white and purple is what does it.
Why do you hate freedom?
Why would you select against people reading your article?
Why would you select against `; drop database prod;?