We don't always get the response from people that we expected after doing something good, but that doesn't mean you shouldn't try. More times than most you get good responses anyway. We have to do good when we feel the need because you never know who it will end up impacting.
In all likelihood, good deeds will not result in a net positive outcome for oneself. Good deeds are usually done to people in a lesser position than ourselves. If our motivation for good deeds comes from the desire to appear "good" and morally superior to others, this effort may be justified, as most people are ignorant and will fall for the ruse. Kindness may also be justified when the likelihood of return is greater than 50%. Otherwise, it is simply wasted time and energy.