Did Russia send Kazakh people to gulags for speaking/teaching own language like it did in Poland, Ukraine and many other places? Might have something to do with resentment.
The USSR colapsed less than 30 years ago.
This has been true for a long time and remains true now much like Russias nature.
https://translate.google.com/translate?sl=ru&tl=en&js=y&prev...
https://www.sas.upenn.edu/~haroldfs/540/handouts/ussr/soviet...
It existed in general, but it was especially intense from 1930s until early 1950s. So during Stalin in particular a lot of damage was caused. It's not hard to point out at all.
See some references here: https://sh.diva-portal.org/smash/get/diva2:1164774/FULLTEXT0...
(from page 107).
But I think I'm wasting my time here. If you want to deny historic facts, do it elsewhere.