So your logic is, we use it here so it is correct to say it wrong? Bacon logic.<quoted text>
Both forms are acceptable. "Hear, hear" was used when people were in agreement with a person speaking i.e. in person. "Here, here" is used more frequently and although it may not be to your liking, most of us posting on here (no pun intended) get it. All of us have moved beyond English 101 and get our point across spellled correctly or incorrectly. If you're "here" for a spelling bee or English class, you're on the wrong forum, we no longer care.
BTW, I never use the phrase.
Hear, hear is an expression used as a short, repeated form of hear him, hear him. It represents a listener's agreement with the point being made by a speaker. In recent usage it has often been re-analysed as here, here, although this is incorrect.