Water is the least clear element in astrology, and Pisces (along with the XIIth house) tend to be the least understood water zodiac sign.

This is partly due to the nature of its rulers: Neptunian and Jupiterean energies are far from being easily defined (in opposite to rational Mercury and Saturn). Jupiter and Neptune are in the core of where creativity, inspiration and seeds for any creative thoughts are pre-born. Therefore, they are in the process of setting a direction for your ship: if used well, you may have a vision that exceeds the abilities of any other sailor on the board - this is much more what a human mind can do; if not, you would be lost in unclear illusions and dependent on horrible winds. At best, with Jupiter and Neptune on your side, you may reach the gods realm; at worst, you may end up as a slave in the hells. The guiding star which leads you either to one or to the other place is your ability to access true inspiration.

That's how Pisces energy works. Humanity is bearly able to make a constructive usage of it, thus Neptune has a rather poor reputation confirmed by the observed behaviour.