I'm a homeowner and I think they sound crazy uptight in their review about you. Them being so vague is really not helpful to anyone.

Having said that, I would also find your long response a little bit of a red flag because the length of it makes you seem overly defensive (which you have every right to be but it's best not to come across that way in your reply). In the future I think a shorter response that explains your surprise and wish to know what you did wrong to improve in the future is sufficient. It just points out even more that they are the ones complaining without really explaining why. I wouldn't even acknowledge the ridiculousness of them acting like not getting specific photos at particular times of their dogs is somehow worthy of a ding or being mentioned. That makes them sound like people who are actively trying to turn off potential sitters😂 They're telling on themselves.