Let's discuss the "Wobble Head" Neurological disorder ..

[Daigga]

Has this always happened with this morph or is it due to in-breeding?

I have said before but the simple fact is that wobble gene to wobble gene pairings is often fatal in offspring, or at the very least rumored to be. Because of all these stories, these genes are probably the least inbred of all ball python genes. you don't breed spider to spider, you don't breed champagne to champagne, etc. There are a very small handful of offspring that have survived, certainly not enough to throw back into the gene pool with any effect.

Because of this I think it's safe to reasonably say it's the genes themselves, not the methods of the breeders.

Edit:
Consider me super offended if anyone tries to insinuate to me that my Giovanni (lesser bee) or Dizzy (bumblebee) are abominations because they have spider in them or that I'm a terrible person for planning on breeding them (not to each other obviously).