If by general consensus you mean the observations of 400 ish bionicle fans on the internet, then yes the story wasn't that complex. However, as Altair pointed out, for a young child and compared to most toy lines it was reasonably complex, we just saw it as a let down because it couldn't hold a candle to G1's very complex storyline.
Your point about sales is very flawed, of course there are places where bionicle sold like hotcakes; near where i live is one. You cant say someone is making up a "big lie" about sales just because said product didn't sell as well in your area. Even if you are basing your views on sales from what you've seen on here, the world is a big place, we could all easily not be near places where bionicle did sell well, even though some of us undoubtedly live in areas where bionicle did sell well. There are so many shops etc which stocked bionicle, our small community can only have visited a small amount of these, so many shops our community didn't look could have had bionicle as a top seller. Also Lego described the sales as "solid" so for intents and purposes it did "sell well". You don't need to be fully engaged in something to see whether it is selling well either, I'd say the fact she was the one buying the sets is a good enough view on things to make a judgement on how it appears to be selling.
You aren't "the rest of people either" making claims based upon a small online community's observations is just as bad, you can't judge something worldwide based on your own very small and limited point of view. And then by extension reach the conclusion someone must be lying, claim it as fact and claim "Lego must have paid them". The sales of a product aren't the same everywhere and vary wildly between areas, have you visited all these areas and seen how bionicle is selling? No - well then in that case you cannot say how something is selling in someone's own area when you haven't seen it yourself.
Just because we are living in a digital age doesn't mean every single kid is addicted to, or more interested, in tablets etc that other toys like action figures and the like, and therefore more interested in taking those, rather than toys, into school That is a very broad and generalised statement that isn't necessarily true. Why do you think companies like Lego are doing so well if kids care more for technology than "traditional" toys now?
@TeslaEffect that sentence makes no sense? All I can gather is that your saying 1 kid doesn't equal every kid, which is obviously correct?