While many internet-goers believe using abusive words as terms of affection is a relatively new invention, in fact this is a long-standing part of traditional folk humor. It is yet another example of the unity of terms split apart by the Enlightenment’s insistence on binary oppositions. 
 Clearly this greeting is not meant harshly. (You can tell by the exclamation mark.) Praise and abuse just fit together naturally - “precious” is praise, “pox-ridden” less so. Since people rarely feel either entirely positive or negative feelings toward anything, let alone other people, some confusion of the two is expected. Such confusion happens in Sam Lipsyte’s also delightful The Ask:
I vote capitalism, which is most adept at making people hate themselves. Here are some funny quotes from The Ask about capitalism. (While on the surface it may seem that I have given up on this paper, I am actually executing a highly subtle parody of the way capitalism compels people to give up. Were this a Swiftian-style satire, the parody would be less subtle, but the humor would no longer be ambivalent as the carnivalesque form demands. It would be entirely destructive and not much fun. On the other hand, had I actually given up, the jokes would no longer have any point at all. The carnivalesque form demands subtlety, an essay which both makes and does not make its points.) Here are some bullet points.
Of these examples, the most sympathy lies with the doughnut shop boy. Winning the game of capitalism is infuriating and losing it is annoying (once you inconvenience anyone else); violent impulses, on the other hand, are understandable. How could such a capitalist nightmare come about? It is the culmination of Montaigne’s complaint, way back ten pages or five centuries, that sexual language is unacceptable for polite society but violence is just fine. Academics cannot begin referring to certain historically fucked countries as “historically fucked,” never mind that the phrase is more accurate than “developing” or “undeveloped” or “third world”. Developing is the least descriptive adjective a country can have - no country is completely devoid of developments. Historically fucked has advantages in accuracy and tone. Why speak neutrally about a status that is emphatically not neutral? Neutrality is a stifling concept, one Bakhtin thought was antithetical to natural language. “There are no indifferent, neutral words; there can only be artificially neutralized words,” and it seems blasphemous to end or begin this sentence with ‘he said’. I only quote out of love; love and affection are second cousins or something; “historically fucked” is an affectionate term. Yet, fucked is a forbidden word. Bakhtin had some of his own words for those who forbid it:

None of these magazines are actually named Fellating Rich Whites, because fellating rich whites is a subject the representatives of authority take very seriously,6 and serious matters must be shrouded in secrecy. They set seriousness in opposition to widely available truth, and in this you would think they finally agree with the jokers on something. You would be wrong. Bakhtin writes that “true open seriousness...is aware of being part of an uncompleted whole.... True ambivalent and universal laughter does not deny seriousness but purifies and completes it”. The carnivalesque embraces truth and seriousness, while the seriousness of Enlightenmentesque7 censors is always on defense against itself.
