When Bitcoin price idump, its difficult to get profit in ICO and some of ICO is fail.
This is reason why ICO isn't recommended to earning.

1. Low Profit

Most of ICO when their token listed in Market/Exchange, that price is always under ICO price. There are 2 ways to escape. Sell with low price and small loss or Hold and wait their price pump.

2. Wasting Time

Every ICO have time to open their token sale. They will close their token sale if hit their target. Some of token sale is take up 30,45 or 90 days. Some of ICO will not stoo their token sale if not hit target. After recieved tokens, they need to listing in exchange so, you must wait again. Better if they not lock that token long time.

3. Most of ICO are scam

Its difficult to see good and real ICO. You can't predict what ICO will giving huge profit and success. Not all success ICO is trusted, they can scam too.

4. Most of ICO need KYC

Some ICO is need KYC to make their security save from buyers. But, giving your identity its dangerous and not all ICO will keep save your Identity safe.

That's only my reason why i didn't trust some ICO again.