A PC isn't defined by the processor architecture.
You're right, an abacus is also technically a PC. But people are hoping a shared architecture will make for quicker development times and better quality PC versions of multi-platform games. Either way the quality should improve somewhat, just because of upgraded processing power and memory cap.
And just to annoy spoffle a bit. Spot the PC version.
Console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, pc version, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port, console port.