Your opinion about Pokémon trackers "sucking some of the fun out of it" is dead wrong. However engaged with Pokemon Trackers to shutter them absolutely sucked 100% of the fun out of Pokemon Go for a lot of people.
Pokémon Trackers enable players to engage in self-selected, self-directed, emergent gaming behavior. This emergent behavior means that people are having fun playing in ways you never imagined...and you just crippled their fun in favor of making everyone play it "your way".
I urge you and the rest of to embrace what the Crowd builds - then monetize it. +Niantic and could have made another $10 million dollars this week, if you'd instead embraced the work done by , leveraged it, and posted an official tracker app in the store for a buck.
For me? Racing the clock to catch an unusual Pokemon turns a walk into a jog, and with the stroke of an email (Cease and Desist, maybe?) you stopped tacitly incentivizing gameplay through allowing me (and others) to self-direct my gameplay via PokeVision (I played for 3 hours yesterday, collecting Pidgeys and Rattatas and visiting Pokéstops to refill) and I've walked more in July than I have in 10 years), and you instead incentivized removing the app and going back to playing Pokemon on the DS while I'm sitting on the toilet.
I don't believe that's the intended effect.
Trackers were absolutely hitting the servers hard, and they had every right to shut them down. Also, yes, using third party tools to mine data from the game absolutely gives you an unfair advantage, especially when it comes to finding the Pokemon that dominate gyms that would otherwise be rare finds.
They are working on adding tracking and more features. This is Niantic- compare Ingress 3.5 years ago to Ingress now. Adding features over time is how they roll.