I support Kuma and his sentiment, though having some competitive experience with the game I might also drop my 2 cents on it.
I think it probably boils down to the way we play the game. Take the traditional (Emblem Lord made a good post on it that I agree with and realised my own way of viewing the game fit into that structure quite well) way of looking at it through advantage, disadvantage and footsies + neutral. In Melee, neutral was supplemented by a heavy offensive, aggressive game, where characters who couldn't keep up were ones that weren't good aggressors/didn't deal well with aggression. In Brawl, the opposite is mostly true. Brawl's defensive mechanics made punishes the optimal way to go, so defensive options were preferred and your way of getting into advantage was by punishing someone from neutral... it was more complex than this; but it's a decent basic way to explain it.
In smash 4, I think people are approaching it using one of these two mentalities. Much of the mechanics are very similar to Brawl and you could consider it a very defensive game... except punishes are generally harder to achieve across the board...
Actually, I find it significantly harder to punish aggression in this game than I did in Brawl. On the other side, aggression is also hard because getting in without using laggy moves like dash attack that actually can be punished requires you to go through footsies and I think that's where the crux of this game lies. Unlike Brawl or Melee, this game idolises two opponents trying to put themselves in the advantaged state against the other, and the most common form of this is a game that utilises both defensive and aggressive tactics to do so. For instance, spacing aerials in order to be safe, trying to poke the other's shield/find an opening to work with. I suspect they've balanced it around this idea (and in this respect it's similar to more traditional fighters btw) and the cast is more balanced than in previous titles; but it means in these early stages of the meta, most game plans revolve around good spacing or characters that have good risk vs. reward in footsies that allows them to really push their advantaged state - If diddy gets past footsies you are in for a world of pain, moreso than if someone like wii fit trainer does. However most characters can to some extent play this footsies game, thus I think why it feels more balanced.
But basically what this means is that for a while the meta will feel very repetitive until more optimal ways of playing footsies/getting people into the advantaged state are found, and that's probably why it feels so stale to people. In response to that, all I can really say is, the meta is literally 2 months old; problems for this will probably be found, so while I respect criticism for this game, I also think our perception of the game will change drastically over the coming months and onward into the year ahead. Thus why I agree with Kuma. Our perception of this game is naturally affected by our perception of past games; but be aware that it will change, so try not to be the prophet of doom on this game's competitive viability when realistically, that hasn't been determined quite yet.
tl;dr this game is different from past smash games in more subtle ways than we know and it will take some time to fully realise the consequences of that. In the meantime, making a judgement call on the game's viability before that point is a case of counting your chickens before they've hatched.
EDIT: I hope i've explained my neutral game effectively enough and it isn't just crazy talk. Someone who knows more about can feel free to tell me how wrong I am, but I think the overall point is pretty solid, at the least.