For me, the Foursquare of today is a more accurate, more up-to-date Yelp. I find it more useful now than when it was first released as a check-in app. Not all pivots are net negatives.
I was an avid foursquare user when it first came out. Going to a place your friends hadn't been felt like you were an explorer charting new territory. I used it for years until check-ins were split off. Swarm felt like it was built to be neglected. Like Netflix with Qwikster, they wanted to focus on another area of their business to secure their future and the existing users were a distraction/liability. But given that either pursuit is nothing without engagement, and they had more location-based engagement than anybody, I don't understand the decision making in throwing all that away.