Real Estate is a business and it's a business where buyer (and Sellers) are dealing with what is for most the largest sum of money they'll ever deal with. Buyers and Sellers don't know the business end, are often too emotionally involved and generally speaking despite what they might like to think are not suited for handling the transaction on their own any more than they could serve as their own lawyer or doctor.
While I certainly won't not show a property that's entry only, I don't enjoy it and know it's going to be twice as much work if the deal is going to get consummated.
So, one would need to ask themselves how do they feel about getting their transmission worked on for their automobile at a certified service center (with a business license) or do they feel comfortable with their own capabilities.
If this is how you want to be known, go ahead and give that kind of service.