If the commit has technical merit and should not have been reverted, why would you not focus on demonstrating why the technical merit of the commit in question? Claiming that a commit was reverted for personal reasons instead of defending the technical merits of the commit strikes me as naïve.
A highly competent person who has produced some work product that was challenged would typically either defend it on merit or assume they might have produced a lesser work and seek to understand why.
My experience in all areas of competence I'm familiar with is that histrionics like those observed thus far are often comorbid with demonstration of the Dunning-Kruger effect in inexperienced individuals.
Zed Shaw is one of the few people I can think of that would be a counterpoint to this observation, demonstrating high competence when acting histrionically. You can just look at his contributions to open-source to see how good he is at what he does.
JAH's github profile (for an engineer that worked there for a long time) seems conspicuously sparse to me. There really aren't many projects there to demonstrate superior mastery of HTML, CSS or git.
https://github.com/nrrrdcore?tab=repositories
Looking further, like at her blog repo. There are .DS_Store files committed (which would normally be in a local .gitignore or in your home folder .gitignore file) and the first file I clicked on the in CSS folder has Jekyll ruby errors printed to it:
https://github.com/nrrrdcore/nrrrdcore.github.com/tree/maste... (DS_Store file from 2 years ago still there)
https://github.com/nrrrdcore/nrrrdcore.github.com/blob/maste... (broken blog post is 6 months old)
Assuming this is representative of the quality of her commits, Occam's Razor suggest competence may be the reason for reverting the that css commit.