What do you think about me turning down a guy I met on a dating app because he was too tall?
Why would you turn down someone for being too tall?
I'm also too tall, I can't find a date who is my height
If you don't think you two would be a good match, then it's perfectly fine to turn him down. You shouldn't go on a date with someone if you don't think you'd like them. However, turning him down based on his height could be seen as shallow.
I was in the right! It's not like I'm shallow or anything.
You're completely entitled to not date this person, but I feel that judging him based on his height is shallow. I think you should try to look past superficial factors in the future, as doing so might make it easier to find someone that you really like.