If you simply google it you will find numerous respectable much better placed people explaining that. A few examples:
Why I find Iota deeply alarming
When I first learned about Iota, at Hack The Valley in January, my initial interest was quickly tempered by scepticism when I learned about…
MIT And BU Researchers Uncover Critical Security Flaw In $2B Cryptocurrency IOTA
IOTA, a $2 billion cryptocurrency that supports Internet of things (IoT) transactions, was shown to have "serious…
There is more; I am not trying to argue their points and don’t think I need to. Note that I am not saying IOTA is a scam, nor am I saying that they may not be on to something. I just have an issue with centralized, pre mined token that portray themselves as true blockchains. It basically means if you buy it you are simply transferring wealth to the founders – in exchange for nothing. Once the bubble bursts that is not the model that will prevail. Of course, IOTA could change at that point. Right now it being where it is in market cap is basically the same as where VERI is in market cap in terms of how it got there. Just my opinion of course.