Nobody ever will.
If you had a base that’s way larger than what you’d reasonably need (like the typical giant PvE bases with all altars and even your blacksmith thrall having its own house) - and it kinda sounds like you did based on the “years of work” part… - then all it takes is a report from someone to draw attention to it and you will get the base wiped as well as a suspension (you’ll know at the next restart if you’ve been suspended as that’s when it applies)
If that’s the case, then you can ask for more info / appeal a ban (temporary suspensions cannot be appealed) at Zendesk
Also, you can check this thread to see if you can figure out a potential reason for it based on whether you did any of the listed things