I dunno I feel a lot of these discussions come from people who didn't actively do melee tournaments (or any tournaments) to begin with. Back when melee was newer a lot of people couldn't wavedash or hadn't found a way to make it totally practical in a match. L - Canceling, dash dancing, chain grabs, grabbing out of shield, edge guarding were the things that were probably used the most. Once people got more comfortable the meta was high movement using wavedashing for platform and stage traversal and additional mind games. It is also very needed for space animals because its literally needed to combo from shines. Other characters don't -need- wave dashing as much like shiek or even marth (it's very very useful but you can just do wide dash dances aka ken dash).
I say that to say this: We have no idea how Smash 4 plays or how practical any of its movement options are or if there's some new advanced technique to be discovered. Why you ask? Because the game is not finished and no one can even discover the most basic **** in a day. Day 1 melee didn't look like the melee we have now and those who played smash 4 approached it with old mentality in mind vs trying to explore new technology.
More important than movement options are hit stun, follow ups after grabs, too far blast zones, recovery seeming too safe, lack of punishment for rolls, too much landing lag on some moves, advanced ledge games, and other things. Movement is important, but wavedashing per se isn't. I think dash dancing and being able to change your pivot positions would be sufficient and with the other stuff I mentioned added, you could have a whole new type of game to play that might still be aggressive with the new added nuances we haven't gotten to play with.
While brawl is very competitive, it pace is too slow and, for those that aren't hardcore to that following, is very hard to watch. This isn't an opinion as brawl itself has a very low viewership vs Melee and Project: M. Even in the FGC Marvel vs Capcom 3 has the highest viewership due to its aggression and flashy gameplay. It is exciting to watch. Same reason Ultra Street Fighter 4 departed from vanillas zone based combat. Hell even casuals hate watching camping and slow play (see: Zero at Smash Bros Invitational reactions) even though it's super legit strat and requires a specialized skill set.
But, why do views matter! This is something you might be wondering. Views matter because with them you can get ad revenue and sponsorships from various companies which can help pay for venues and expand your tournament region. Tournaments are not free and they have to be hosted at a venue to accommodate those players (along with gamecube / wii and tv setups some of them purchase and provide). Those venues can cost money and some tournament organizers pay out of pocket for the love of the game, but if the community were to expand it needs those higher up companies to support them OR a dedicated fan base. If there isn't enough fans / viewers, the base will not be able to support a larger scene. ALSO, if the contention does not seem challenged enough or it feels like the games ceiling gets hit very early in terms of improvement, it causes fatigue among the tourne goers causing them to quit. If there is no competition, there will be no tournaments despite how many fans there are (see: skull girls)
In closing, we need to support Smash 4 on release to see what kind of game it actually is vs trying to push it into a bracket before it actually finishes being balanced. We have facts that they are catering to a tournament based setting as well as a casual one which before, during brawl, the focus was to actually close the skill gap and neuter the tourne scene so that mentality shift in development is a huge step up. Be vocal about what you think should be improved, but don't be ignorant enough to suggest the game should just revert to melee. Let it be its own identity but still aggressive enough to be competitive. We don't need old techs back but we do need mechanics in game that allows us to be free enough to play how we like and give us the abilities to push ourselves infinitely just like Melee and M. Also, remember Melee isn't perfect. It's got horrible balance issues which is why Project M has been increasing in popularity recently. Variety and freedom of combat is king!
Oh, one more thing. I've been seeing some casual people saying that they wouldn't miss the mechanics or don't bother learning them anyway. If that is the case, doesn't that mean if they were included nothing would change? The only thing that would be different is that there's more options instead of less. The game itself doesn't change at all for you so why would you want to take options away? If you feel like these techs undermine the amount of time you've put into the game personally, than the cold reality is that even without them the top players are going to eclipse anyone who doesn't put in the time whether its 1 button all items on high w/ hazards or regular melee mechanics. You can't escape practicing so why take away tools for those who want to enjoy the game for decades and still improve? Conversely, tourne players, why not give the game a fair shot when it comes out and actually find out what it really is about vs judging without even playing it (some **** talk even without doing as little as trying the demo which I luckily did get to play).
Haha this is long but its very exhaustive and I hope people understand more about what we actually need to do as a community for this game.