Just my opinion.
Old school D&D has the emphasis on the setting. Megadungeons, fantastic castles, Tombs of horror and Temples of evil – these were the things that players hurled themselves against to gain gold, glory and the satisfaction of saying “I survived.”

Makes sense when you look at it from the aspect of a wargamer – wargames are about surviving the scenario. The scenario is all – players are merely units to perform orders and fight battles to see who will overcome the whole of the scenario. You might make history, you might rewrite history.

Of course, that simplifies things to a great degree, but I think it’s a valid point – and explains why the rules were about rulings, but the dungeon/wilderness were emphasized.

Fast forward to New school D&D. This has the emphasis on the player’s experience. Supermages, fantastic fighters, dealers of spells and might. These players complete quest after quest, gaining levels and even more power ups.

Makes sense when you look at the far reaching market of RPGs today. These are people who grew up with CRPGs, video games, movies bringing formerly imagined stories to life and literally huge fantasy worlds involving millions of people. The rules for min/maxing a person to start out as a superhero rule. This also simplifies the modern gaming experience, but again, I think it’s a valid point.

Neither is better than the other in the sense that at the end of the day, if you’re having fun, then it’s a Good Thing.

For me, I grew up on the old school. I like the old school feel and the old school spirit.