Even if everything you say is true, it is inherently wrong as well as unproductive to refer to ethnic/religious groups as "barbarians" based on the actions of some portion of that groups behaviour. It essentialises the group even though there are countless Russians who dont support this behaviour and therefore aren't "barbarians".
Behaviour can certainly be barbaric and referred to as such (I would have had no problem if the original comment said "the invasion of the Ukraine by Russians is barbaric" as an example), but referring to entire nations/ethnic groups/religions as barbarians based on a portion of that group's behaviour is deeply dehumanising and one of the most toxic ways to engage in these sorts of discussions with very negative outcomes for both sides by denying other people their humanity.
Can you name a single time in history ever where framing conflict in such a manner has led to anything positive? Because I certainly can't and there are PLENTY of examples of it being done. However much some people may relish the opportunity to finally have an "enemy" they can dehumanise and hate, it is always ethically wrong as well as being counter-productive to do so no matter how good it might feel to some people.