So the street takes Apple's figures and add 20% because they know Apple always understates by 20%, so on those figures Apple didn't do as well as they should have.
The problem is that you don't know if Apple really expected $30Bn and under-performed or really expected $25Bn and over-performed.
Apple is a public company with shareholders and has a legal(and moral) duty to actually produce honest figures. Ultimately massaging them down is just as bad for investors as talking them up.
AAPL didn't lie. they're just conservative.
If you are deliberately underestimating to be conservative - so if there is an earthquake in Japan you can still make the expectation, or you do it to produce a headline, it's equally bad for your shareholders.
Otherwise why not produce figures saying we might sell nothing next quarter -if an asteroid wipes out all life on earth.
Of course it's still a nice position to be in compared to a company lies about making a profit next quarter hoping for a miracle!
wrong. read my other comment above.