I've often asked the question and have never received the answer, but suspect that many wire aerials might have been for HF transceivers. HF has ability to propogate by bouncing off of the ionosphere and thus can achieve MUCH greater beyond-line-of-sight comm.
As the war progressed and technology marched on, VHF likely became more efficient. Perhaps this is the reason that mast mounted (blade type) antennas became acceptable for most european operations. For pacific operations, HF likely continued to be necessary due to long distances involved.