The misconception about L-Cancelling:
In games, there are two main operations: Actions and Executions
Execution = button inputs (moving the control stick, pressing A, etc)
Action = the result of button inputs (running, jumping, etc.)
As a player, you have to perform a certain execution to get a desired actionfrom your avatar. This means that player decision making is entirely focused on actions. Actions change the state of the character and thus, offer different advantages and disadvantages. Once a player has decided to perform an action, they are forced toexecuteit in a way that the software is requiring them to.
So when people criticize L-cancelling for not having a risk-reward mechanic, you should ask yourself: is L-cancelling an action or is it a required piece of execution?
My belief is that many people are incorrectly judging L-cancelling on the merits that it is an action. The fact is, L-cancelling is not the same as running, wavedashing, jumping, shielding, etc. L-Cancelling is actually an operation comparable to pressing the A button or moving the analog stick.
Key Idea:When you decide to do an aerial, and for sake of argument, lets say it was a forward aerial, you do not say: "there is no risk reward to pressing the c-stick forward vs. not pressing it forward." This is because you knowingly subscribed to make the correct inputs upon decided to do that action. L-Cancelling is the same thing, you don't L-cancel to put your character in a different state with a risk-reward dynamic,you L-cancel because you chose to perform an aerial near the the ground.
If you are going to criticize L-Cancelling, you need to criticize it on the grounds that it feels arbitrary as an execution based operation.
TL;DR: L-cancelling is really just an extension of executing an aerial; it isn't supposed to have a risk reward relationship so you can't criticize it for lacking one.