i am not dio kin

Jonathan's hamon abilities are so strong from the very beginning because he's so full of love and passion, all for the people and things he cared about so fiercely. What he's channeling isn't the sun, it's life itself. The most painfully symbolic part of hamon as a concept is that it's what ties all living things together. the very nature of human connection is brought from hamon.

Dio failed to ever truly connect with anyone else in life, when he kills someone to drain their blood it is like he's severing that person's love, relationships, their passion for living-- its so much more than just eating a couple prostitutes sometimes. Vampires don't feed on people just because, they drink blood to sustain their hamon. They have to leech the very essence of life, of human love and joy, to keep going because they lacked those things in life. Dio becoming a vampire is just as symbolic as it is literal.

Vampires at their core represent self-sabotaging, bitter, lonely people who refuse to let others in. The only way they can live is by killing others, severing human connection and happiness and love and destroying it with them. They don't get happier themselves, they just destroy.