A new feature DeviceCheck on iOS11

Apple’s new feature is called DeviceCheck and, if developers choose to use it, it will allow them to fingerprint and persistently track users’ iPhones, even if a user deletes the app or wipes their phone completely, using Apple as an intermediary.
Here's something everyone should know
http://bit.ly/2siq7bP

This is actually bad, isn't it? I don't want any developer or company to track my movements even when I have deleted the app. You, as developers, what do you think?

It's unethical and will really piss of iPhone users.
People don't like apps, that are built in their systems without the possibility of easy uninstalling it - how they will react if they find out, that they are spied all the time, and they can't stop it?
Hope it's just a dumb idea that won't be applied.

After reading the article, I realize is more like saving historic data of the app used on your phone. So for example if you use a trial of an app, it expires, you delete the app and try again (even with a new account), the app system will have saved that the phone has already enjoyed the free upgrade.

But yes, I guess this is the case explained to calm down people, but of course, it can be missused.

The feature has its pros and cons, both at the same time.
As it can be misused to some extent but if we need to delete any application for some point of time and don't want the data to get disappear so that when we reinstall the application and track the data to retain it, it can help.

Thanks for the clarification.
Well, that sounds reasonable but what if I will sell my phone to someone else...?
Let's be honest, not everyone knows how to wipe out his phone completely before selling it.
What will happen then? I wouldn't want to give some of my personal information to some strangers...

You have got a genuine matter of concern, but the application's data is actually linked with your Username and Password.
If the other person installs same application with his/her username and password (in short a new account) its impossible to fetch other account's data, hence its safe.