PC development is cheaper:
Consoles require a royalty payment which various depending on console.
Console gaming does not yet have a full game digital distribution medium yet which is cheaper than dealing with physical distribution and retail.
Development kits are the same PC's you already use for development instead of purchasing expensive console development kits as well as your PCs.
PC development is easier:
Games are built on an architecture that doesn't change every few years but expands on an already existing library of knowledge. You're not having to learn a whole new architecture and environment with every 2 new games.
All development takes place on the same PC environment instead of fighting with a console development kit as well.
The volume of 3rd party middleware for PC's far outnumbers that of consoles.
No TRC's. Console companies demand that every 3rd party game follow a TRC (Technical Requirement Checklist...even though not everything is specifically technical) which can skew game development in a direction the developer may not want to go in and put undo strain to ensure it meets those demands. This is not a quality control manner for those wondering.
Controls are easier to map and develop.
The rEVOLution is not being televised
