Wired connections have some properties that wireless connections don't:
Robustness: a wireless connection can be subject to various forms of interference (think to microwave ovens) and obstacles, that can affect the quality of the received signal.
Latency: wireless connections make a large use of acknowledge signals and error checking codes, due to their lower reliability. This means that you need to wait more for valid data.
Parallelization: while you can run 10 cables to transfer 10x signals, with wireless links it's harder because you will have interference and a limited amount of channels. This applies also when you have many networks in the same place.
Security: with a wire you (almost) always know where you're sending the signal, and getting into a wired network requires at least to get access to the cable. With wireless connection the thing is much harder, because signals are broadcast in the air. Encryption systems are evolving, but with GPGPUs and parallelized computing it's becoming much quicker to make brute force attacks.