User Rentention Stats on nerdculture.de...
As you can see in the screenshot, the usage of new users after some months is very low.
I don't know if that is specific to nerdculture.de or a general trend on all instances after the large influx end of last year?
This seems like a fair move to me, system space is valuable, plus even though you are not collecting and storing that much data, you still do some of this, so if the user is not using the account, then in theory there is no need to keep hold of that data.
Do other instances have similar policies of data / user removal?