Banks: Crouching punch does a different kind of punch than standing still. Forward+punch often does a different kind of punch as well. That's a pretty weak counterargument.
You *could* say that there should be a special button for fireballs, where holding back does a weak fireball, neutral does a medium fireball, and forward does a fast one... but then what about uppercuts and hurricane kicks? The special move mechanic is designed to give characters a varied moveset with SF's chosen button layout. You'll also note that Sirlin, in his HD remix redesign for Super Turbo, made certain character's specials less difficult to execute; his exact reasoning is that the game is about the decisions you make, not unnecessarily complicated inputs.
Is a wavedash unnecessarily complicated? No. It arises naturally from the game's engine. You jump to leave the ground so you can airdodge, you airdodge to use its momentum to slide along the ground. It requires practice to do consistently with multiple characters, but it's logical.
Skler: I also think you're underestimating how long it takes for the average player to master L-canceling. Fifteen minutes and you L-cancel perfectly under complicated gameplay situations? It took me over a year to be effective at L-canceling, wavedashing, and short-hopping during actual gameplay, and I still messed them up constantly. Admittedly, I'm not a shining example of technical talent, but that was a huge barrier to overcome before I could even start thinking about the game strategically.
I'm a more technically sound player now (constant practice for three years will aid even the untalented), so please don't assume I'm complaining because I don't want to put in work. I love practicing. But there's a significant time investment where there is no reason to have it.
The question is simply this: why should there be a special input to cancel your lag when you always want that input to happen? I don't always want to dash, so there's a difference between walking and dashing. I don't always want to short hop, so there's a difference between short hops and full jumps. I don't always want to wavedash or waveshine, so different commands are required. Why is a special command required when that command is the only viable thing to input?
And for other slippery-slope folks... no, this doesn't mean your f-smash should always magnetize you to the opponent because hitting him with the smash is always the superior option to missing. You know that's ridiculous. I shouldn't have to explain why, but I guess I will.
1) In teams with friendly fire, your teammate is an enemy for all intents and purposes besides the victory conditions of the match. Your forward-smash now magnetizes to him if he's nearby. Great.
2) This nullifies the point of dodging, rolling, and using any evasive maneuvers because your f-smash always hits when you input it, eliminating strategy and turning the game into "who f-smashes first."
3) Oh, but wait, it doesn't matter who f-smashes first, because TIMING is involved in connecting with your smash, and we're eliminating that too. So as long as the smash hasn't hit me yet, mine will also keep me safe.
Of course L-canceling is a skill. I could also argue it takes more skill to perform in Skler's balance beam example if people throw pies at you while doing your routine, or if you had to whistle the entire time. Just because something becomes more difficult and requires an extra skill doesn't mean it's more deep or strategic. It's just harder.
Without it, I guarantee you the smarter players who make better decisions and who practice more would still win. The game would still be fast paced and challenging and difficult and deep, and it would even continue to have more new blood who weren't discouraged into believe they needed years of practice to even start *thinking* about the game. It would shift focus onto what the game is actually about, because I promise you that Smash is not, at its core, about punching the trigger button every time you land.
Edit: ridikulus, your name is remarkably apt. What other technical skills could there possibly be to practice in Melee besides L-canceling?
Certainly not waveshining, wavedashing, short hopping, timing your fast-falls around hit stun, spacing on sweetspots, spacing in general, SH-double aerials, moonwalking, pivoting, DJC'ing, shield-dropping on platforms, platform-cancels, auto-cancels, wavelands, JC'ed shines, de-syncs, chaingrabs, wavedashes out of shield, JC'ed grabs, float-canceling, shine-b-airs, up-smash out of shield, buffering tilts... None of those. Nope.