First of all, No-CD are NOT cracks.
A No-CD patch is made to avoid wasting of time to regular users that
have bought the original game NOT to let everyone to use copied games.
The problem in fact are the methods used by the games'vendors to
"protect" their games.
A CD protection means that everytime you wanna play with your preferred
original game, you MUST lost time finding the CD, removing any previous
CD, inserting it in the drive, waiting some seconds to let the hardware
to load it and finally launching the game hoping the CD is not damaged
or the drive is able to read it at full speed.
How many times you wanted to play a game but then you didn't because
you was too lazy to find the CD?
Then suppose to have an enough old game that requires the CD to run but
the CD is a bit damaged or your Cd drive is not able to read it, what
you do?
How much times you have broken pieces of your rooms and computer
because you was too much angry with your CD and CD drive?
But is not finished here because encrypted executables (safedisc,
securom and so on) and anti-debugging techniques are incredibly bad for
who wanna try to patch or to solve a problem in a no longer supported
game or understand where is located a possible bug just found in the
game.
That's my thought about No-CD and CD protections.