You're not really wrong that "official SBR tier lists" are not necessarily better. This is in large part why there is no such official SBR tier list for smash 4 (nor is there a BR for 4 in general). For older smash games extremely seasoned experts can give realistic impressions of the relative merits of the good characters versus each other and reach meaningful conclusions when collaborating for a tier list. For Melee and Melee only, such an utterly absurd amount of time has gone into the game it's even realistic to talk about low tiers (the lower half of Brawl tier lists to this day is poorly explored and often unrepresentative of actual character quality, just an inevitable consequence of how not enough time went into the lesser characters to accurately rank them versus each other). For a game as new as 4, honestly, tier listing at this point is basically just posting character lists to have fun; anyone who believes he can, by any means, create a list with any respectable amount of accuracy in this game is at best overly optimistic. For vague accuracy of good characters, it tends to take around 6 months. For real accuracy of good characters, it takes a few years. For real accuracy of good characters and vague accuracy of bad ones, it takes about a decade. I don't know how long it would take for real accuracy of all characters since it has never happened in any game that I know of; probably at least 50 years of constant competitive play would be required which is more than any game will realistically ever get.
For what it's worth, extreme and obvious tier claims are almost always ballpark right. I think we can say, safely, that Diddy Kong and Sheik are in some way good characters. Zelda and Mii Swordfighter are probably not very good. These things will almost definitely continue to prove true for the game's entire lifespan, and the rough ideas of "good versus decent versus bad" are already growing to be understood and are likely mostly right with a few errors (the rub is that you can't know which characters are the ones we're wrong about). If you wanted to know the relative placement versus each other of, say, Wario vs Shulk vs Mega Man though... honestly, the best you can say at this point and be sure that you're right is that no one knows for sure. Since this game is fairly well balanced and relatively few things are just obvious and drastic, you have this situation where we all agree on a few top characters, we all have our own views of several more characters we each individually think are also top (and there's no way to know who is right), we all agree most of the characters are decent with no real collectively certainty of relative merits so on most tier lists the difference between being rank 15 and rank 40 isn't even that meaningful right now which is more about what we don't know than anything, and we all seem to think a few characters are bad but have little agreement over precisely which ones are the real stinkers and how they fare versus each other.
In short, a community voted tier list is probably fun for some people, and I think it's great since tier discussion is about nothing but brainstorming ideas as a group and having a fun time. Meaningful conclusions are just impossible right now and honestly will only begin to become possible right around EVO time (and even then, only really for the high parts of the tier list). I don't think we should be scared or hyper-critical of tier lists existing since they're fun and can be a proxy to communicate other kinds of information, but let's not pretend like any of these lists have any real accuracy since we can be pretty sure they don't.
Man, this makes me want to post a really inaccurate tier list while I'm at it, but I think I'll just get some sleep instead.