^Nobody is saying to "REMOVE ALL SCIENTISTS". Of course you need some sciences on board. Just not every disicipline that you would need for say.. exploration. And to have them onboard would be putting them in harmsway.
Janeway never took part in the Cardassian conflict, having been stranded in the Delta quadrant long before the war began.
I assume
Wormhole is referring to the "Cardassian Wars" that began prior to TNG, not the Dominion War.
EDIT: Ninja'd by
Wormhole!
Out of seven major departments that have been identified in one way or another during the shows, I'd say that science would probably have the fewest number of people that remained on front-line assignments with high combat potential during the war. That said, I still think a relatively small number of science officers would actually leave their normal assignments for this reason, and most of those would probably be noncoms. In Trek, it seems as though a full officer gets considerably more cross training via the Academy, and noncoms tend to be more focused on their primary role, with far lesser training outside of that (not sure how true this is in real life). Hence, any commissioned officer would be more likely to stick around, regardless of department, but a noncom science officer's skills, being so heavily focused on their particular specialty, might dictate they transfer elsewhere. Whereas the primary skill set of a noncom, say, Engineer, is still going to be useful in a combat-heavy scenario.
Pure scientists would still have their uses, as has been pointed out; you never know when you are going to run afoul of some insane phenomenon or spaceborne entity. Between that, and those science officers that can double as additional medical, operations (ops officers seem to be computer whizzes to some degree) or engineering officers, plus the odd science officer who just happened to put in an unusual amount of time training in tactical, security, piloting, etc... Again, I think the number of science officers that would leave their normal postings because of the war would be higher than any other
single department, but not by much.