wrong on both accounts. Near impossible to play fighting games? Why? The functionality of the keyboard is exactly the same as a gamepad for this. They're completely neutral. Theres no advantage or disadvantage. Theres literally nothing, not a single thing that a controller does extra over a keyboard. This is another myth that propagated without merit.
The biggest myth is about platformers. Which are actually BETTER on a keyboard. Its not even difficult. Take a controller in your hand. How do you use the dpad? You have the thumb which needs to activate the four buttons that form the dpad. And your right hand for the action buttons. Now place your hand over the arrow keys on a keyboard. How does it sit? THREE fingers over the buttons at all times and a miriad of keys for every function imaginable reserved for your left hand. Platformers on a keyboard have increased functionality over a gamepad and offer BETTER controlls over gamepads.
M/kb isnt better for games with guns. Thats a side effect. Theyre better for every game with free camera controll. Which is near every game in every genre. They offer faster and better functionality in all aspects of a game's design. You can access everything in a game faster and better. Better, faster and broader access to a game's functions. Its a better tool in near every instance.
Ummmm.
I'm a mouse/keyboard crusader. The Xbox 360 was almost irrelevant to me because its flagship genre (FPS) was dog shit with a gamepad. I watch in dismay and disgust as people buy $400 game systems with $60 games plus costs of DLC so they can play a game which they don't even know they can't control properly.
I find it INSANE.
But it's even more insane than that to propose that mouse/keyboard is better than a controller for platforming games. The above example makes about as much sense as suggesting that you drive with two feet so both the gas and brake has a foot on it at all times. BETTER CONTROL, AMIRITE?
I cannot fathom that the person who wrote this ever actually beat any 2D or 3D Mario or Sonic in his suggested fashion. It sounds like someone who tested a keyboard in Green Hill Zone Act 1 for two minutes and said "yep, it's better!"
In a 3D platformer, where 3D movement accuracy is critical, what are you going to do? Move using the arrow keys and control the camera with the mouse?
Go back to school and play Super Mario 64, then try again.