I see my confusion. I assumed the "why" used was about why they chose to do it that way, because the characteristics of it that cause it to look bad are obvious and don't require an explanation.
It's hard to do right. When it's done well (the font designer spent time making sure all the letter pairs look good together), it's totally invisible and thankless. But when it's done poorly, like in this case, it really jumps out at you.
Interactive web mini-game about kerning if you want to try your own hand at it: https://type.method.ac/
Auto-kerning is one of my favorite features of Adobe products (as opposed to many other graphics & text editors). Even when using a font that doesn't have a built-in "kern table" that the font creator should've included to optimize the "most beautiful" spacing between any two letters, Adobe can algorithmically guesstimate it using their "optical kerning" system that tries to estimate an ideal spacing based on the look of the adjacent characters: https://helpx.adobe.com/incopy/using/kerning-tracking.html. Some open-source software, like FontForge, can also try to guess: https://fontforge.org/docs/ui/mainviews/metricsview.html
And ... man that's a mountain out of a molehill kinda problem.