Molog Bal, Daedric Prince of Destruction, created the vampires. But the disease is named Sanguinaire Vampiris, after Sanguine, who is the Daedric prince of debauchery and dark indulgences. Why would it be named after him?
I am gueesing it has something to do with the Literacy/Literature within Skyrim. Remember, She was part of the Imperial Empire, which uses the Latin language, which is why many words may be influenced by it all across Skyrim.
Tbh if you ask me, Latin Language is pretty much the Lingua Franca in the Skyrim game (well except your convos with your fellow dragon-related buds like Greybeards, Parthuumax and Alduin, who partially uses Dragon Language when speaking to you). I don't know about the other sagas though like Morrowind.
In previous games it was called porphyric hemophilia which makes a lot more sense, but nope, we gamers is tu dum tu understud that hemophilia as in liek hemoglobin ie blud and philia as in liek or luv menes luv uv blud and therefour vimpirism. thonk gud that buthesduh were smert enough too translate it so even us gamers can no it is vampire disease. y they no make it just named vampire disease? me mind have make effort with this cryptic naem uv "Sanguinaire Vampiris". me nede it to be speled out and litteraly shuved down my brain that it is vampir disees. god, I can barely stand to read my own ripping into the low standards of intelect that Bethesda must have of us who play their games.
Hemophilia probably referred to the actual, real-life condition, which comes to mind way faster for most people than its etymology. However, hemophilia is a disorder which prevents blood clotting, which actually doesn't make more sense because vampires don't bleed to begin with. It's cooler, I agree, but Jesus Christ if you're going to complain that they changed it, do it coherently (yes, I know you were proving a point).