Although random drops were possible in the oldest Castlevania games, they weren't common. Certainly nowhere near as common as current CV games, that's for sure. Random drops (well, okay, controlled drops if you knew what you were doing) were vastly more common in the various Zelda titles. Link could be assured of drops if he killed enough enemies.

Not that Alucard is above looting corpses. He did it all the time in Symphony of the Night. He just likes to act better than everyone else.
 
    

When evil spreads across the land, and darkness rises and the monsters roam. When the creatures of the night make beautiful music, and the things that go bump in the night go bump with greater enthusiasm. When the world is in peril and is in need of a hero...

These guys are, sadly, the best the world can hope for. These are the adventures of the heroes of CVRPG. They mean well, they try hard, and occasionally they do the impossible...

They actually do something heroic.