Particular hulls stay relevant for a limited amount of time, but Crews can be be useful indefinitely.
It is annoying to player Pirates to come across Crews that favor a hull that has long been obsolete. And it comes up repeatedly and often as Pirates use Crews everyday.
It reflects poorly on the maintenance and current state of upgrade of the game. This causes Pirates to question the leadership, capability, and commitment of the game developers; and thus becomes detrimental to player morale.
Favoring a type of hull such as Forsaken or Draconian is OK as long as there are currently relevant hulls of those types.