It's more than just that though. I still use a tracker, so I'm not too butthurt about PokeVision, but there's a lot of changes that do annoy me:
- Pokemon that are way more aggressive and harder to catch. Yesterday I had 5 Pokemon (CPs ranging from 80 to 300) in a row that ran away after breaking out of the first ball I threw. Before the update, Pokemon barely even ran.
- Graphical updates that make the game run slower in battle and menus. Other people I play with experience this too.
- The Nearby list now doesn't even show what's closest to you and furthest away from you. The tracker I use shows that I currently have a Jigglypuff and Kakuna right next to my house, yet the Nearby list shows two Rattatas and Pidgey, then on the second row Jigglypuff, Weedle and Kakuna. So even as a "soft" tracker, the Nearby list is absolutely useless.
- The update introduced new glitches. The biggest of these is that Pokemon on the map are other Pokemon in battle, and possibly in Gyms too (
see here).
But most of all, what has been mentioned throughout the thread the most, absolutely no transparency or communication from Niantic. People want certainty about whether or not the in-game tracking will return, and they want to be able to communicate to Niantic about the new problems they're having. The company is doing some really shady **** right now and they will naturally lose players if they continue down that path.