Well, not just that, i have a feeling people are not informed very well about the limitations of the weather forecasting. Naturally, those who get wet will complain.

Most weather forecasts have rather coarse spatial resolution, they can't resolve small scale processes like local rain events very well.
So, it may be raining, but few kilometers away. Also rain droplets may evaporate before they reach the ground. Etcetera etcetera. Weather radars provide huge improvement, but normally they are used only for monitoring current conditions or very short scale forecasts.
Also, forecasting is easier for some areas than for the others. Prediction skill for the North Atlantic European shore may be better than somewhere in South Pacific where weather/climate is normally more wild.
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The more money is invested in high performance computing and weather observation programs the better weather prediction will be.