I've started wading through this stuff myself this year
And as far as I know I keep picking them because like another has mentioned, they are familar. They are comfortable. They are my Dad, just in a different form.
And I suffer from the illusion that I am missing a part of me. A part my head tells me, a partner will fix. NOT. It's all a load of garbage and most importantly it is not true but until maybe 8 months ago, I couldn't even identify that. I am unsure I could even put how I felt into words.
I'm slowly learning that getting 'excitment or entertainment' from realtionships is not very healthy. Dunno if it will ever change, but I have been told awareness (about myself) must come first, before something can be changed.