I think they are obsessing unnecessarily on the semantics of what "development genes" are. I strongly doubt there is a bright line separating developmental gen

I think they are obsessing unnecessarily on the semantics of what "development genes" are. I strongly doubt there is a bright line separating developmental genes from normal steady-state genes. A multicellular organism is one hugely complicated, parallel, state machine. If certain states become unreachable, that doesn't necessarily mean all the genes responsible for those states are no longer doing anything.