Why is IOTA only traded on Bitfinex and none of the other exchanges?
IOTA is now traded on Binance too. Enjoy.
The reason it has taken so long is that IOTA is not a Bitcoin, Peercoin, Ethereum copy-paste and has a fundamentally different mechanism which makes it non-trivial to list on an exchange.
tl;dr : IOTA is on Binance. IOTA is not easy to list on exchanges.