In my understanding, KIWI is just one of the generic ERC-918 tokens.

https://www.reddit.com/r/ethereum/comments/8ekr4z/erc918_mineable_token_specification/

And for all ERC-918 tokens (0xBTC, Catether and more) mining requires a secret key (unless you manually sign all transactions), in the present circumstances.
In addition, tokenminer is not developed by KIWI.

I think, the opinion "KIWI is SCAM because it claims a secret key" is equal to FUD coming from ignorance.

But I understand the feelings of people becoming uneasy.
The project should publish the Whitepaper, roadmap, and https://www.liberation.online/kiwi/ asap.