What you're saying about speed not being the only argument used as an argument for melee being better then brawl is absolutely true: there are however people (very few) that claim that melee is better only or mainly because of it being faster. I'm just saying it shouldn't really be a major argument (like you said, it's more of a preference thing)
About the tech skill thing: It's probably true that if Nintendo when making brawl did not try so hard to take away all tech skill in the game there wouldve been more options left (if that was the case, brawl wouldve probably had l canceling).
BUT, if all the tech skill stuff in melee was easy to do, like shffling, l canceling, waveshining, pivoting or just short hopping with certain characters (after lots of practice these things become easier, but really, they are hard, think about when you where just learning it), would the game have less options or have less depth? Not really.
On the other hand... Tech skill does have a role in balancing options: for example, if flatland drillshing was really easy, I'd do it all the time. But as it is now, I'd rather just go for waveshine->grab->uthrow uairs, which does less damage and easier for my opponent to escape.
But on the other hand, if drillshining was made easier to escape aswell (if smash DI:ing the hits in the dair was easy) it would be useless. In fact, Fox's dair would be useless in general since you could just SDI out of it everytime (which would limit fox's options, which would be bad)
Or if perfectly JC:ing shines with fox was easy I could just spam it at people shields until they rolled away, then chase their roll with a perfect WD out of the shine (assuming this is easy aswell) and spam more JC shines until I broke their shield or just hit them through a shieldpoke or when they where vulnerable in the lag from the roll and then combo them off off that. This would obviously be broken.
Or another example: If ledgeteching was easy as pie and anyone could do it consistently, edgeguarding in this game would be useless for any characters that can not effectively kill people off stage. This would make characters who can go offstage to edgeguard overpowered and characters who cant would suck (at edgeguarding which is very important)
This would actually even take away an aspect of the rock/papers/scissors system. For example, sometimes when I am edgeguarded by falcon's dair I meteor cancel instead of edgeteching because meteor canceling is easier so I know I won't mess up. Although ledgeteching really is better, it is risky to do it because it is hard so I can easily mess up (and if I do, I die). If ledgeteching was easy all other options would be pointless, which would take away an element of depth.
So what I'm saying is: tech skill is not an important ingridient in a good competitive game imo. But sometimes it is needed for balancing out certain options (through making the best options hard to perform, like the ledgeteching/meteor canceling example I made), but it should never be the central part of a good competitive game.
It really isn't a problem though, It's not like melee would be better if it didn't require tech skill. I'm just saying it's not that important (imo)
Melee to me got boring faster then Brawl Cause I get tired of fighting computers cause my friends suck. At Brawl I can play with my Internets friends who PWN me. All I hate in Brawl is the SSE. But Metal gear solid 4 owns all those Smash games 
