A usual part of any ICO is it's disclaimer that the project is not a guarantee of a fool proof profit.  In fact, most ICOs does not explicitly tell people to invest, rather, they ask people to support and believe in their agendas.

As to your question if it is the good time to invest in an ICO, the answer is really in your hands.  Have you found an ICO that you believe in? If so, go ahead by all means, otherwise, it would be best to keep researching and trying to learn more of what their project is all about before doing so.