What constitutes the dirt bag look? Sweats? An unshaven face? Dirty shirt?
To answer your question, it’s kind of appealing to look like you don’t care about how you look. Most girls are worried about how THEY look anyway.
It’s hot if you are a well-dressed & dapper man, but just know that no girl wants to compete with a man more vain than they are. Still, don’t change – or settle! You’ll probably find somebody as equally trendy as yourself and you’ll live happily ever after, so look past the girls… towards the women!