Back when the game released, they had a tracker. You could find a Pokemon just by walking around and itd tell you if you were heading the right direction. Niantic went the wrong direction by taking away this feature.
In my neighborhood, there were people running out of their house at midnight, all because a Pikachu was nearby and everyone worked together to track it. It was amazing. This game is nothing without that tracker and will forever be a shell of its former self.
If you want more players, thus more money, bring it back. If it hurt your servers, get better servers. It has a chance of being popular again but the "key feature" needs to be reinstated. It was a terrible idea to take it away and a horrible business decision.
The company, itself, killed its own games momentum! Get the tracker back or the game will never be like it used to.
HimuraKenshin about Pokémon GO, v1.39.0