If an anti-Semite writes an essay arguing why Jews are wrong in every way, we would probably feel personally offended even if not mentioned by name.
If someone wrote an essay arguing why all Ashkenazi or Sephardi Minhagim are wrong, those of that minhag would probably feel personally offended even if not mentioned by name.
If (like what seems to be happening here) some Ashkenazim who eat gebrokts argue that all those who avoid gebrokts are categorically wrong, those who are machmir will feel personally offended. I 100% sympathize with those who took personal offense here.
Just observe, there have been several posters here attacking the overall custom of not eating gebrokts. Yet, NOBODY here has made a blanket criticism of those who eat gebrokts; it has only been the criticism of those maligning others’ minhagim.