I had this happen to me too a few months ago. The prospective guest had no profile filled out at all, no picture, only email verification(I require verified ID). Guest was not answering my questions (what is your full name/town, and that of extra guests, why are you traveling here, please update your profile with basic info and a clear photo of you and verify your ID) After calling Airbnb they told me this was a new policy and if I denied it the block would be removed. I told them that was ridculous as this guest would not even be able to complete the reservation even if I approved it. They essentially said too bad. I have denied very few requests but check out all guests before approving, of course ABB said I should just switch to instant book. I said I would not do instant book whch gos against the original idea of ABB of getting to know the guest. My units are separate apartments but I meet all guests and interact with them as much as they allow(I live next door) I have hosted guests at events outside my home and invite them if I am have a party or friends over for a barbeque or breakfast.
I think this switch is due to the discrimination suite. I also had a few request whicguesth I think were plants. One was a woman that questioned why I wanted more info on her-was I trying to find out her race/religion? I said no I ask that of all guests because I have a responsibility to my family, neighbors and other guests in the building to make sure guests are who they say they are and are not scamming or looking for a party pad. She said she understood and was sorry. Never answered or booked. Another had a picture that looked like an advertisement, and looked familiar. He asked a bunch of questions answered mine said it sounded great, I approved him then he did not book.
I think ABB does not apply the block consistently. I will message the guest if ABB blocks dates and let them know if they do not reply so I can make a decision quickly I will deny request and they can make another when they fix profile and complete ID verification and anwer my questions which I will consider. I also explain that many good hosts do not like to accept guests with little or no info. They usually fix it and request again and thank me for the advice.