Big, slow ships like the Python and Anaconda are the only things I'd consider putting armour on, since the added weight is too much of a trade-off for fast attack ships, but being priced at several times the already massive cost of the base hull (and the associated insurance hikes) make it way too exorbitant a choice for the little protection hull reinforcement and armour packages offer. They don't protect subsystems at all, and if you have to use it you're either in a tense one on one with another player (in which case they'll target your subsystems and, being slightly lighter, outmanoeuvre you to win) or you're being ambushed by a wing (and you're already dead), so right now they just don't cut the mustard in any way.