Before I ever used one, I was outraged about what I perceived as a cheat. However, once I got one, I realized that if I take the game seriously, I need to keep records, and those records need to be as detailed as possible. I write slow, big and sloppy, I tried, barely able to deal with a single table.
All the trackers are doing is collecting all the facts, and allowing you to organize those facts in some way that makes sense to you.
I still can't figure out how to use the "4 bets small connectors oop on Thursday" stat.............
Remember that those stats take many many hands on any player to actually be useful. So if you play the same game and see the same players day after day, wouldn't it be nice to have organized thoughts about each of them?
The trackers can help you make more informed decisions. That's all.