I don't get why people defend incorrect language usage but wouldn't defend terrible misspellings, like "definitely" as "defiantly". They're both equally "wrong"

I don't get why people defend incorrect language usage but wouldn't defend terrible misspellings, like "definitely" as "defiantly". They're both equally "wrong" but one is acceptable and one isn't. I agree that language is an evolution and there is no "wrong", but that doesn't stop people from looking stupid by trying write intelligently and falling on their faces.