At the risk of coming across like I'm defending Batgod, detective work these days is very different from what it was when Batman was created. New technology is going to make detecting a lot more different.
Then again, given how obvious Batman's villains are, it doesn't take the genius of Sherlock Holmes to solve a typical Batman crime.
Detective work is not a solo act. It requires asking questions and employing experts because you don't know everything and relying on your own limited knowledge is a good way to bungle a case by letting your own bias influence you.