I definitely think that it maybe be part of the reason but not the complete reason.  I think that most ICO's that fail is because the lack of execution and not realizing what the the user is looking for, how it is suppose to fulfill a need.  In order to have anything successful it needs to satisfy a specific problem or need.  Questions to ask:

How will this benefit the user?

Is the target user big enough?

Is the use practical?

Is it easy to use?

Does it follow a trend?

Is this a long use coin?

Is there room for innovation?

In short there are many reasons why ICO's dont work out.  Hard to say which is the particular reason.  Just in my opinion anyways....