Learning Curve and dahlias

I love the dahlia gardens that I’ve visited in France but I haven’t mastered the art of growing them well.  This was my second summer trying and I have some questions for more experienced people.  People who actually grow them year after year.  Question 1.  Is this bad genes or something that I did wrong? 

??

 I also had a lot of these (nice!)

dahlia Bilbao

I’m trying to save the tubers, just to get the experience; will I want to use them?