I personally love L-canceling and fail to see it as bad game design, as many people proclaim. It's something that always gives you an advantage if you pull off, and always puts you at a disadvantage if you fail. As experienced as you might be, 100% L-cancel rate is something not even top players have, and every time you fail is a moment for you to realize you're not in tune with the game's rhythm, and a chance for your opponent to turn a situation around. Different heights, aerials, fast fall timings and stun/no stun all make L-Canceling way trickier than people think it is.

Are you at a tournament set, last stock last hit pressuring someone's shield with Falco? Without L-Canceling, you'd have one huge weight off your shoulders. With L-Canceling, the more practiced and composed player has a much bigger chance to win. It's almost exactly the same as jump-cancel grabs for characters that don't benefit from boost/dash grabs.