dhenry:
Advantage of Arduino
Arduino's biggest advantage is that it allows a user to code without looking at the datasheet;
Which is a key to allow newcomers to programming and electronics to be productive much quicker on actually accomplishing something with their Arduino projects. They don't need a datasheet to master making some leds blink as they wish, and to many that is a goal worth reaching before having to mastering reading datasheet.
Arduino's biggest disadvantage is that it allows a user to code without looking at the datasheet.
As newcomer's project become more complex and ambitious they will come to understand the need to learn about datasheets and they will be more motivated because they have an immediate need to.
Why make the entry cost in time and learning effort so high as to have many give up in frustration? The Arduino is about enabling ordinary people to do stuff quickly and easily and build upon early successes.