Airbnb has drastically changed the criteria for keeping a listing on their site. From what I can tell 2 or more 3* or less reviews over a period of several months leads to suspension and possible removal. If you provide low price, no frills type place and do fairly high volume of bookings then this is going to catch you out. I believe this also includes sub categories on the review as well, so having a good overall avg will not prevent removal.
It will also eventually remove the lower priced listings since they are likely to be repurposed spaces and less hotel like. But also affordable and open to criticism of the guest decides they really wanted luxury.