If the word of knowledge/wisdom, or prophecy does not come true, obviously it is false. Christ is not sitting around waiting for these things to happen. His body is alive and well, and doesn't depend on one's word of prophecy/wisdom.
As far as not "questioning", I would definitely be in your shoes! Truly I believe that prophecy has become far more than what God intended for it to be after Calvary.
Truly the law and the prophets were until John (
Luke 16:16) and then Jesus fulfilled completely the law, and now his spirit speaks to our hearts individually.
I believe that the type of prophecy that we saw in the OT was changed at Calvary, and the Day of Pentecost, and now Christ speaks to our own hearts individually through the Comforter, His Spirit indwelling us. When a prophecy or a Word of Knowledge comes, it should be to CONFIRM something that the spirit has already been dealing with us about. Agabus came to Paul with a word of knowledge and prophecy... but Paul had already heard from God before this, and knew it was a confirmation that he was to go, because first he had already heard the Spirit speak to him.
So, I think this demonstrates that prophecy or a word of knowledge/wisdom comes to us as a confirmation of what the Spirit has already been dealing with us personally about. I don't believe it is necessary for prophecy to foretell future events, because in my opinion, just as you are stating, most of these "prophecies" never come true, are false, and simply emotionalism. (not to say that there are words of knowledge/wisdom that never come true... because I do believe Christ does speak to us in that way also... they just need to be weighed for their truthfulness, and judged) .