This is really tough because the only purpose of Grindr is to give it your location to see who is around you. There also needs to be much stronger requirements for end user transparency about where their data is going.
Seeing that someone is 100 ft away is a common start of a conversation. Maybe they live in the same apartment, at a local coffee shop, work in the same building. Which leads to... well...
That doesn't excuse the privacy issues though.
The types of people that open with "I'm 50m away from you" are super freaking creepy.