Only up until very recently did Crypto as a whole break away from it, and BitConnect just happens to have its foot in both.
Saying cryptocurrency only recently broke away from this is just a conclusion of your premise, which I disagree with entirely due to the existence of material like Bitcoin's whitepaper. To say they are on the same spectrum is just misleading.
However, smart contracts and the adoption of the blockchain by technology's bigger players has provided some validation to what's happening. Regardless of the white papers, and how one individually assessed the thesis, it didn't have market adoption and it wasn't as if BTC was actually producing something. So investing in BTC (a virtual commodity in limited value) had no real business purpose.
So crypto was in the same boat as ponzi schemes, until very recently. Now it's being taken seriously due to providing actual value.
The only thing BTC is really good for right now is to act as an intermediary between it and alts--since you can buy BTC and ETH with fiat, then transfer those to alts. BTC isn't a valid currency for transactions for a variety of reasons. It is simply the backbone of the crypto economy at this point, and the grandfather of the technology--so there's some lure to it as a limited asset that, so long as someone wants it, someone can sell.
The world is not black and white.