Seeing as you are FO due to someone reading you that you don't want to (IRL) then surely you can understand why people choose this option?
I personally don't let people view my diary if I can't view their diary. That is my preference. If you don't want me seeing your diary then why should I want you to see mine?
I have set my diary up MO/FO. I have one MO entry and the rest FO. Reasoning for this is that way people don't get that "been blocked" note when clicking in to my diary, and there is still a way to view my diary and say hey, you seem alright based on your entry and FP, so hi wanna add me kinda thing. It's worked for me for 2.5 years and will continue to no doubt.