Different companies create new coins and make it public for the people to invest on. And if it makes a good fortune on the market, it will be established as a good coin. That's a simple policy.
I just think the companies that make their own crypto by merely attracting capital from ICO projects are a new trend for businesses in 2018. So some companies of Technology releases its own coin to attract investors instead of raising for capital as usual.
Capital is the main thing whey they are creating their coins this time. Remember almost all of major coins have started from the ico. that's why so many people are still interesting to buy more and more ico dude. It's just a like very big opportunity when you are investing in the ico but that will be involved a very high risk.