There are two reasons why it's bad:
a) Sony used to have 70% marketshare with PS2, the PS3 has around 20%.
b) SCE loses a lot of money on the PS3 and will probably have its 3rd negative financial year in a row. This will hurt everything from game development to R&D for the next Playstation. As you say the PS2 and PSP should make quite some money, so the PS3 evaporates the profits from these consoles. At this moment it already made more loss than the combined profits of the PS2. I hope everyone can see that this is a bad thing.
20 million isn't bad perse, Gamecube made money in fact, but I don't think anyone expected it to be this low.