infosecslave said in a dead comment:

    [...] you have to consider the fact that Truecrypt project
    was started before FDE was popular, maybe their goal all 
    this time was to popularize such encryption. With XPs 
    demise that goal would have been achieved as every  
    current Windows version comes with Bitlocker.

Your comment is dead but makes a lot of sense, especially in light of the message on the website:

    The development of TrueCrypt was ended in 5/2014 after
    Microsoft terminated support of Windows XP.

I don't agree Bitlocker is a sensible alternative, but this piece does fit the puzzle.