This is great! Another aspect of electronics that one must get used to is that there is usually more than one way to interpret every part of a circuit. And this

This is great! Another aspect of electronics that one must get used to is that there is usually more than one way to interpret every part of a circuit. And this current-sink point of view is quite useful -- as you point out, it immediately suggests a way to improve the circuit: Put in a better current sink, like a transistor.