The reason? I'll tell you why I believe they did it. It was boring playing a straight caster in older editions of the game. You had very little you could do until you were able to cast one of your six daily spells or picked up a potent magic item capable of being used multiple times per day.
Ubiquitous magic has become the standard to give players more to do with their tools. Potter was hardly the first world to have ubiquitous magic. In Lord of the Rings magic was being used all the time and was considered to some races like elves in the same way we look at technology at one point in the history of Middle Earth. In the time of Sauron prior to becoming a shade, the creation of magic weapons was as common handguns in America today. You'll note that there were a total of 20 rings of power created and the mention of many other minor magical rings. Gandalf, Elrond, and Galadriel wielding the three rings could do magic at will as could Sauron and Saruman. Even Aragorn knew of magical healing remedies he could use at will combined with elven chants.
The nature of magic depends on the world. Original D&D was a magic light world as far as spellcasting went at low levels. I think now it is more a magic as technology world, which is more common for users of magic. The way created worlds usually limit magic is to limit the number of people with the ability to use it. Unless you're a jerk DM, you generally don't do that to your players. But you could if you wanted to limit magic.
Then again PCs are considered extraordinary people. Though magic is common with PCs, it isn't common with NPCs. The vast majority of the world can't cast spells. PCs are a lower percentage of the population than 1%. Probably 1 out of every 10,000 or even 100,000 people even have the potential to be a PC.
I don't see it as a big deal. Magic was probably too rare in AD&D. It may be too ubiquitous now, at least the flashy magic. I think it gives casters more to do and makes them more interesting to play. I think that is the main reason for the changes.
Ubiquitous magic has become the standard to give players more to do with their tools. Potter was hardly the first world to have ubiquitous magic. In Lord of the Rings magic was being used all the time and was considered to some races like elves in the same way we look at technology at one point in the history of Middle Earth. In the time of Sauron prior to becoming a shade, the creation of magic weapons was as common handguns in America today. You'll note that there were a total of 20 rings of power created and the mention of many other minor magical rings. Gandalf, Elrond, and Galadriel wielding the three rings could do magic at will as could Sauron and Saruman. Even Aragorn knew of magical healing remedies he could use at will combined with elven chants.
The nature of magic depends on the world. Original D&D was a magic light world as far as spellcasting went at low levels. I think now it is more a magic as technology world, which is more common for users of magic. The way created worlds usually limit magic is to limit the number of people with the ability to use it. Unless you're a jerk DM, you generally don't do that to your players. But you could if you wanted to limit magic.
Then again PCs are considered extraordinary people. Though magic is common with PCs, it isn't common with NPCs. The vast majority of the world can't cast spells. PCs are a lower percentage of the population than 1%. Probably 1 out of every 10,000 or even 100,000 people even have the potential to be a PC.
I don't see it as a big deal. Magic was probably too rare in AD&D. It may be too ubiquitous now, at least the flashy magic. I think it gives casters more to do and makes them more interesting to play. I think that is the main reason for the changes.