Harris was chief of the Windows User Experience for Windows 8. He created Windows 8. He created Metro UI. He created the Windows 8 Start screen, charms, allowed ads in its inbox apps (e.g. Weather), etc. Keep that in mind when Harris says things like "the Start menu is Microsoft's flagship user experience. It should represent the very best UI design the company is capable of."
Did you read the article and see what he was complaining about? He typed the word "Chrome" and the top hit was a web search with a bunch of ads on the right-hand sidebar. His complaints were 100% justified and imho correct, and the immediate jump to ad-hominem attacks rather than debating the content of the article seems uncalled for.
It's fair to not take any UX advice from the person responsible for the Win8 start menu serious, that was a much bigger UX turd than Win10 or Win11 could ever hope to be.
sorry, but this is one of the few cases where its justified. Anyone whos developed on Windows since 7 or before (raises hand) knows how awful Window UI has been since 8.
You wouldn't want Richard Nixon (if he was alive) commenting on Obama's term would you? Even if Harris is 100% right, its just tone deaf and in bad taste. No one want to hear his opinion on Microsoft products. Hes done enough already.
His personal history contextualises his point, which is distinct from criticising his personal history at broad.
For example, had I said "Barry designed the new start UI. He also has received several speeding tickets" you could make the claim that I am making an ad hominem attack on Barry, since the only reason I would bring up the speeding ticket is to make Barry seem less responsible. His speeding does not affect his ability to design a start menu nor does it influence his design decisions.
However, if I said "Harry has been seen criticising the new start UI for being inconsistent. Harry previously designed the new Settings menu in Windows, which was also inconsistent", there are some important differences to take account of. Specifically, the fact he was involved in the development of another feature in the Windows product, AND it can also be criticised for the same failing that Harry has now applied to the start menu gives us information ABOUT Harry's criticism.
Now we can say "Harry is going to come at this from the perspective of someone on the team" and "Harry has made the same mistake before". Depending on the details of Harry's comment, that could make his comment less trustworthy, but conversely it can also make it more valid.
Calling that an ad hominem is, in my opinion, excessively reductive, and in the case of contextual data being added that is contextually relevant, not appropriate.
