Why isn’t there one exchange for all Alt coins?

[SpceGhst]

I started mining Alt coins this past February (I know... not the best time to start), and have amassed small positions in 15 different coins.  I decided I’d like to consolidate my holdings into Eth or BTC so didn’t have so many coins to keep up with.  I was doing some research last night as to which exchange to use and found I’d have to sign up for at least 4 and possibly 5 different exchanges to consolidate the way I want to.  I own coins from Ethash, Equihash, and Cryptonight algos.

So, why isn’t there one exchange where I could swap all my Alt coins to Eth/BTC?  Kind of like the US stock market where there is the NYSE and NASDAQ.

[Polipog]

There are many different business exchanger site in cryptocurrency, and they are all different on the system of price offered also, but it is good to trade on official exchanger sites on your tokens or coins stocks, because it delivers the level of good price balancing system. And it is also good to have a lots of exchanger in order to find which one are good.