Your concerns about the frequency of hammer formations suggests that's also the focus of your trading - find a hammer, open a trade. In fact, successful trading is not about finding the best type of entry pattern. A short-term entry pattern like a hammer is the least important element of a trading strategy and over-focusing on this alone is likely to mislead you into false positions which are ultimately not going to make a great profit.
Obviously, this is not unique to hammers, the same goes for all short-term candlestick / chart patterns.