A good friend of mine told me the other day that; Batman is more popular than Superman only because he is a human and more relatable than an alien with superpowers. Being a fan of Batman and reading Superman, i find that completely wrong. 
Yes, Batman is a human being and so are we, and last time I checked none of us are aliens with powers. But as much as I have always wanted to relate to Batman since childhood, I cant. If my parents were to die infront of me, I doubt I would ever wear the cape and cowl and fight crime. Being relatable can mean very different perspectives. What people dont realize is that Batman is no where near an average person. Through his training, he has achieved 100% human perfection and the peek of human conditioning. No one in this world can say they have trained since childhood and gained this level of skill. Not to mention his 127 mastered martial art forms and his genius brain. When reading his comics, the only thing any one can relate to, is the loss of loved ones and seeing death. But Superman has seen that too. The other perspective is his psyche. Batman is a very angry person and focuses only on the mission of bringing justice and fear to those who deserve it. While at the same time, pretending to be a joyful Billionaire. if you were a schitzofrenic, then sure you can be Batman all you want, but would you be rich and have mastered all human skills? 

Now for Superman. I honestly dont like the character and I find the comics very linear and uneventful unlike Batman comics. But I still read them because part of me feels a lot like him. If I can say I relate to a character yet dont like him, well thats saying a lot. Lets look at Superman's origin. His planet blew up and was launched into a spaceship resulting in him landing on the Kent Farm and being taken in... hmmm what does that sound like? Adoption process? I am pretty sure alot of people feel like they have no home they can say they are from. Second, Superman constantly feels alienated (no pun intended) and metaphorically shunned that he cant truly be a human. What I know about growing up is that; as some point, you will feel alone and misunderstood, like you dont belong with certain types of groups and feel like you cant offer anything. Yet people get over those bumps by embracing their differences and try to build a life. Superman has done this. He has landed a secure job, a wife and a proper life living on Earth since he was born. He did not just arrive in his 20s like Kara El. He grew up there and faced the world by being different which everyone is. Yes he has superpowers that define most heroes, but he uses them responsibly and is in control of them, which many people feel they need to, Superman juggles family and saving the world, people juggle their own issues. Superman saves lives, so do cops and firefighters. If Superman inspires people then that means people see him as relatable and thus want to do good, like him. 

In conclusion, Batman is the greatest human being to ever live and greatest superhero for that matter, but  he cannot relate to people, which makes his comics so intriguing because, people read comics for entertainment and taking a break from reality and seeing the darkness that Batman brings. Superman may not ever be one of my favourites, but I can see all my emotions in him and sometimes with my talents I feel like I have superpowers.