Predictions are intended to provide a rough planning framework; they are clearly not expected to materialize as stated:
By necessity predictions are based on assessments/opinions of/about the present. Assumptions about the present and future are then extrapolated from those assessments. These assumptions are needed because information available for planning purposes is always incomplete. In turn, these assumptions are the point of departure for predictions (and then decisions and plans) for the future.
If making these predictions were easy or certain, company executives would not make the kind of money they do. It is (or should be) obvious that this prediction process is inherently flawed and uncertain. It is therefore also obvious that predictions about the future are educated guesses. They are essential to guide actions today that will prepare the company for that future - but they are guesses.
Anyone who has done any serious planning at all for anything should understand this basic truth. In that context is should be equally clearly understood by anyone who has even skimmed a safe harbor statement that no certainty can be ascribed to forward looking statements (i.e. educated guesses). THIS IS NOT A DIFFICULT CONCEPT!
It follows that inexperienced investors, or people who expect a risk free investment, have no business investing in stocks - especially biotech stocks.
The ambulance chasers know that safe harbor satements exist specifically to cover the uncetainty of forward looking statements - but, if they can make enough of a nuisance of themselves, there may well be a (small) hand-out for them to go away.