Rav Gifter explained the svara:
Or some other suggestions...
The Nesivos Shalom said that the magnitude of the holocaust was just too massive for any fast day to
commemorate
.
So paskened the Chazon and Rav Moshe Feinstein
This is Rav Moshe's lashon
Yo"d 4/57/11
Some argue that you don't pasken halacha from a kinah
Rav Herzog held that the whole pshat is incorrect
A lot more to discuss.....