Why do Marxists/socialists have such a visceral fuming hatred of the mere concept of countries?

Like seriously

A british version of the internationale literally includes the lyrics 'and end the vanity of nations'

They also simultaneously talk about national liberation i.e. helping oppressed peoples fight for sovereignty/independence and thats all well and good...but reminder that socialists' end goal is basically the total global abolition of all government,global anarchy where all laws and ethnic,cultural,etc. distinctions between people are destroyed. That comes off as basically sadism to me. Whats the point of supporting someone's 'national liberation' if you plan to eventually destroy all nations and identities?

Is anyone else utterly horrified by this? Socialists want world anarchy and division,they consider loving your country 'bourgeois' and just want an international soulless dystopia. If they win,we all lose our homelands and identities...