There are fewer than 100 exchanges, and there are fewer than 10 trusted exchanges, fewer than 5 well used and trafficked sites and that is nowhere near the number that would make it worth posting here. I do not know what you think would be a better number, but you have picked a strange number to attack, there are way too many coins, too many invested ICO's and such, but the exchanges are right where they need to be.
I must say you have a huge list of trusted exchanges! I use a few major ones which I might score 6 on a scale of 1 - 10 for reliability, and perhaps I would "trust" decentralized exchanges like Waves with a 8 score. Then again, I don't have to trust Waves or any other Dex to use them and that is their biggest advantage over the others. Whatever balances they say I have on my wallets, I can verify on any explorer.
Poloniex et al can say whatever they want me to see, and I will not be able to breathe with relief until I get my coins back from them.