A blockchain is just a string of hashes, where every next hash depends on the previous one.
The hashing ensures that the data you have matches the data you had before... And that's it.
Even a non-developer can make a blockchain.

The hard part is not making it, but convincing people to trust you with their money.

In cases like BitConnect and similar networks the data that gets hashed is probably who lenses what and who received what gains.
But that only means that they can't claim that you never gave them any money. You have that security at least.
However it doesn't mean that they can't just... Stop working.

In your place, I'd read the terms and conditions very very carefully.

• What happens with your money if they stop working tomorrow?
• Can you sue them if they do? By the laws of which country?
• Does the country of origin of the network even consider Bitcoin a currency? What if by their laws blockchain contracts are the same as contracts for exchange of in-game items in World of Warcraft?