Many times I've had to decline a reservation request because the guest wants something that is against my house rules/policy. Yes, I agree sometimes asking or explaining a situation may get a host to change their mind (ie. a reservation request with kids when the listing says no kids) but not always. Either way in this case if I don't want to make the exception I'm penalized. If I just don't accept or decline then I'm dinging for not responding within 24 hours since responding via chat doesn't not count as responding or I'm dinged for declining a request if I hit the decline button. When I called the SuperHost line about this previously their response was to ask the guest to withdraw their request...that doesn't seem helpful either.
Additionally, since I require the potential guests to provide some information about them and their trip before I accept the reservation (I rent a room in my home I have to screen carefully) if the guest doesn't respond to my message/question in a timely manner I'm forced to either accept a reservation I'm not comfortable with yet or decline it and then get dinged.
Yes, hosts need to be held to standards but don't make it so difficult to adhere to those standards because without good hosts and properties you aren't going to have guests either.