Joseph, which rabbonim objected to Yom Hazikaron? Name some, please. Do they compare in any way, bechochma uveminyan, with those who objected to Yom Hashoah?
And I don’t care who selected the date, or why. It makes absolutely no difference. The fact remains that this is the day that people remember them, so it has the same status as a designated yortzeit. In the absence of any halachic problem with the date (as exists for Yom Hashoah), there is simply no reason to insist on remembering them on a different date instead.