To be fair to the Kazakhs, and I have a fair bit of experience working with them, they are very much rule followers, as opposed to rule-disregarders or ignorers.
I don't know for sure what happened with the Fokker, but two things are sure.
1. Pilots who work there know a lot about ice, iceing, deiceing etc. It's meat and drink to a Kazakh pilot.
2. Fokker pilots surely know about its reputation when carrying ice- any ice.
I think this'll turn out to maybe be undetected clear ice, or some unfortunate combination of circumstances- perhaps including a weight and balance issue, rather than recklessness.
Kazakh pilots are very wary by nature.