No, there is no evidence to suggest that PF intentionally wiped out old users who didn't post. It is more likely that their accounts were simply deactivated due to inactivity.
The exact number of old users affected by the supposed wipe out is unknown. However, it is likely a small percentage of the total user base.
It depends on the specific circumstances and policies of PF. Some websites may have a process for recovering inactive accounts, while others may not. It is best to contact PF directly for more information.
There could be multiple reasons for this, including server space, security, and maintaining an active user base. Additionally, if an account is inactive for a long period of time, it is possible that the user is no longer interested in the website and their account becomes irrelevant.
Some websites have a feature that allows users to temporarily deactivate their accounts, rather than having them permanently deleted. However, the best way to prevent deactivation due to inactivity is to log in and post or engage with the website regularly.