Because Wired will ALWAYS be better.
Even under the best case scenarios, with the best wireless broadcaster (which most basic ones by IPS or bought are not), and best wireless receivers (again, most built into things are pretty poor).
You will still sometimes be limited in speeds... as well just straight off the bat, you will usually have less latency.
Start moving away, interference, etc.. things start lessening.
Your will always be more guaranteed to get better performance if wired.
Rogers 9865, LG 47LV5400 LED TV, Onkyo HT-R690.