Let me start by saying that Batman is one of my top five favorite comic characters of all time, but the amount of hyperbole and PIS surrounding him, is just stupid, at times. Lets have a look at why.
1) Beating characters who are way too powerful for him.
Now I am aware that Batman has some cool weapons and toys, but when he beats guys who can destroy the planet he is standing on, it is pure PIS. If you are asking yourself "self, what is PIS," you are probably a movie watcher, who needs to stick to movies, and leave this discussion to real comic fans. "Batman has kryptonite." Ok, but Superman could fly thirty feet in the air, and laser Batman's head off, without ever getting close enough for kryptonite to be an issue. He is BaMAN, not BatGOD!
2) But with prep time...
No doubt Batman has an incredible mind, and an abundance of resources, but lets just compare him to Dr. Doom. (I am fully aware that they exist in different universes, before someone takes the time to point out the obvious). Batman owns a large portion of a large city. Doom owns all of a small country. Batman has a lot of toys. Doom has an army of doombots. Batman is one of the best hand to hand combatants in the world. Doom has excellent hand to hand combat skills, and even without his armor, has sorcererey comparable to Dr. Strange. Prep time would benefit Doom just as much, if not more, than Batman
3) DC is SO dark.
This is another uneducated myth. I challenge anyone to find any DC comic as adult as Alias, or any piece of DC cinema or TV as dark as Daredevil (especially season 2), or Jessica Jones. When people say DC is so "dark" they are usually talking about Batman, and he isn't the darkest thing going.
4) Hyperbole and PIS.
Batman has beaten guys like Hulk, who can take shots from Mjolnir. Batman may have kryptonite, batarangs, and yes, even shark repellent, in his utility belt, but he has nothing with the stopping power of Mjolnir, and Hulk hits hard enough to topple gods. Batman simply couldn't hurt him, but PIS writing allows him to do things that no mortal, no matter how strong, dedicated, or skilled, could do. If part of the attraction to Batman is the fact that he has no super powers, don't write him like he does.
Batman doesn't have the most annoying fans, of all time. That honor belongs to Goku, and I have already done an article on that topic. He does however top a lot of "greatest superhero of all time" lists, and frequently wins "who would win if" tournaments. One, right here on Moviepilot had a final four, consisting of Batman, Silver Surfer, Professor X, and Superman. Superman and Batman ended up in the finals. Batman could, in no way, beat Silver Surfer, who is capable of destroying the planet he stands on, or even the solar system, he lives in, and he could only defeat the Professor, if he somehow managed to get the drop on him, and considering that Professor X could sense him, a mile away, that is highly unlikely. Also, Batman is not the oldest comic character in existence. So what makes him the greatest? You could make the argument that he has enjoyed the most commercial success, but that is about it.