I don’t know if the foundation-wipe raids are a widespread problem or not. I know at least one player on these forums has posited that they’re the biggest problem caused by the 5th encumbrance perk and I’ve also seen at least one thread complaining about repeated foundation-wipes.
Like I said, I started this thread to get everyone’s input, especially because all my ideas about balancing this out in PVP are based on my guesses and other people’s stories.
Which brings me to another point:
As I also disclosed elsewhere, the polls here are meant to be informative. I knew from the start a lot of people wouldn’t take them that way, but I thought it wouldn’t matter, because we’re here to discuss things and anyone who actually referenced the polls as an argument would get a reply from me explaining that they’re not 
The reason why I included the polls in the first place is because I really want to see the distribution of people who aren’t satisfied with the status quo, i.e. how many think the perk should be removed, how many think it can be changed, etc.
Lesson learned for the next time (if ever): include the polls without the status quo option and explain why the polls are missing that option. I made a mistake there and I apologize for it.