To be fair, it's any software and any software company. Microsoft just gets more flak because more of us use more of their products - statistically, Microsoft products dominate the marketplace and this causes anguish when what we hope is designed, wasn't designed that way.
Lately I have enthused over Outlook 2007 Categories - not just colour names, you can assign new Categories and rename existing Category tags so that they are more meaningful - like VIP, Must Do, The Boss, The Wife - you get what I mean.
One of the nice things about Outlook in most aspects is that if your machine dies, you can rescue or keep safe your stuff by copying the .pst file before hand. The .pst file contains your Email items, stored in whatever folder hierarchy structure you designed, your Calendar, your To Dos and so on. Except Category customisations. It appears they may be stored somewhere in registry like HKEY_CURRENT_USER\Software\Microsoft\Office\11.0\Outlook\Categories
It's enough to make your cry.