1. Unless all you play is a sit down driving or flying simulator, the wires will get in your way. You can mitigate it with ceiling and wall pulleys, but it's still a really terrible experience that kills immersion.

2. Fitness. If you're moving and turning a lot, you're just going to hate wires. Your arms will slam into them and you'll almost trip on them and pull your computer down.

Wireless to a desktop isn't perfect, but it's doable. Stand alone is ideal if you don't the visuals being turned down a bit.