I mean, the Crossfield class was constructed specifically for researching spore drive as a potential warp alternative, so we have to assume the spinny saucer is a required part of that technology and the structural weakness is a necessary trade-off.
Obviously the off-screen reason is that it looks cool.
I do wonder why Discovery and Glenn are NCC registries though rather than NX - given they are the only ships of their class, and experimental in more ways than one.
I mean, the Crossfield class was constructed specifically for researching spore drive as a potential warp alternative, so we have to assume the spinny saucer is a required part of that technology and the structural weakness is a necessary trade-off.
Obviously the off-screen reason is that it looks cool.
I do wonder why Discovery and Glenn are NCC registries though rather than NX - given they are the only ships of their class, and experimental in more ways than one.