You're right, few of the mentioned exchanges are actually well-known. They seem to be using coinmarketcap.com as their source for the 'top exchanges' which is

You're right, few of the mentioned exchanges are actually well-known. They seem to be using coinmarketcap.com as their source for the 'top exchanges' which is basically going off of reported volume with no validation. Of course there are going to be scammer/spam exchanges reporting ridiculous numbers. How about looking at Coinbase, Kraken, Bitstamp, Bitfinex, Gemini. At least those have been around awhile.