What you described about blended families is mostly true. I'm sure there are exceptions to that. I was someone who was opposite. My step-kids called me Dad, loved me. My step-S5 actually calls his biological dad by his first name, and called me dad.
W was the opposite. Even told me that she thought we could reconcile, but we might have to wait until my kids were grown and moved out because she didn't want to deal with them. How insanely selfish and immature and crazy is that?