Hi hi, hello, I just wanna give my two cents on the dating question/situation.
First off: iPhones are social statements. Since they are generally more expensive, 'better' designed and a status symbol. If one doesn't have an iPhone it could mean that the person in question has poor economics, disregard the social or the aesthetic aspects.
Secondly: Many iPhone users believe that Android phones are far less advanced than iPhones.
Last but maybe the most deciding factor is the compatibility issue between the operating systems and that Android often can be like a foreign language to iPhone users.
Many people aren't ready to meet new people, much less date someone and having technical problems plus having to learn a new world called Android. It can be much more commitment for some than others.
I also think this is mostly said about the early stages before you get to know someone.
Hope this helps you understand and please let me know if I missed something.