No. It's not like Diallo is the ONLY player ISU is recruiting and spending time recruiting him is costing them other recruits. You are going to miss on the majority of players you recruit. To go back to your dating analogy. If the ONLY person you ask out is the hottest girl in school then you're probably going to spend your school year alone but if you ask out 30 girls, including the ten hottest ones, then odds are that eventually you are going to have a hot girlfriend unless there is something wrong with you. There's nothing fundamentally wrong with ISU that prevents them from being a landing spot for these elite kids. You don't quit after two say "no thank you".
This is easy to say when you are Kansas and a majority of the Top 30 are on your radar and have an interest because of the name on the jersey. When you are Iowa State, you have to get in on these guys VERY early and only a few are even learning more about Iowa State. Hopefully that will change but right now, KU recruiting Top 30 guys vs. ISU recruiting Top 30 guys is night and day different.