I get what you mean. Its more mellow insult and not as strong as it used to be back then (but still xenophobic). But lets speak in general and not this case specific, as I havent been so far anyway, very demeaning rhetorics and insults being accepted leads to eventually people seeing that group of people as less then human (thats why I really detest the notion "its just words"). And when that happens, its free fall to kill them as you see fit. I mean, we dont have to go far back in history to find notions such as (even to the point its unofficial law): "whosoever kills a Gypsy, will be guilty of no murder." And that was fucking true for a very very long time.
Why does people eventually think fucked up shit like that? Because too many idiots has reasoned its "ok" to insult them and eventually in the long rung leads to thinking they ar lesser humans, and it naturally escalates from there to the stages of direct actions like deporting them, branding them, mutiliating them, sterilizing them (this one happend as soon as few years ago, forcefully sterilized, NO ONE cared that it happend to them) and as its ignored too much throughout history, massmurdering them in gigantic proportions (only difference between the Jewish holocaust and the Gypsies in WWII, is no one cared to not only count them all, but be outraged enough to care to report it, historians has completely ignored it). Just saying, just not the most recent behaviourism towards them, and what it leads to, but in general outright systematic ethnic insults that are accepted, who deem them as lesser humans, should not be underestimated IMO. Because it has bred and nurished one of the most darker of acts of human history, how the majority of people absolutely abhorringly treat a minority of people.
This isnt really specific to the Zlatan insult at all, but just to actually think its cool to spout racist crap, in whatever degree, its screwed up (regardless of the low lifestyle of that ethnic group). And I yeah, the real issue is Zlatan isnt even a zingaro, but the fact is how pathetic isnt, in however degree, a group of people is used as the benchmark for a demeaning insult (not direct, but the fact is they are used as insult because they are thought of as lower then lowest of humans, to the point being deemed subhuman), you arent just insulting a stupid player, but a whole group of people. There is no way to justify that regardless of the negative stereotypes they uphold.
I mean, this mod actually tried to justify this ethnic insult by saying they arent an ethnic group, and they are spread out around the world, like even if it was true (the first claim...haha), that it would make it ok to constantly say constant bigoted crap abou them. He says he lives in Romania, well him thinking its totally ok to be xenophobic about gypsies is not too suprising then, considering how they treat them in Romania.