Hobo Elf
Arcane
Well, again, status works much better for SnS. The difference between a raw longsword and a paralyzing one is way too big for the tiny paralysis to add up. Ditto for poison, really. Look at the difference between the longswords in the bone tree. The raw path hits 672 damage while the poison one slides back all the way to 528. Thats more like whiffing every 4th attack, (78.5% as much damae) which is a pretty huge deal.
The stat shown on the weapons is not indicative of how much damage they actually do when you hit with it. Moreover, The damage is also calculated differently depending on the weapon type. So, a LS with 500 raw will not do the same damage as a Lance with 500 raw, per hit. I'm not sure how it is calculated, but I suspect that it is % based, with each attack doing a different % of damage. The high numbers are just added in for a 'wow' effect. Shit is hella dumb.
With all of that said, you are right to not use LS with a status effect, solo, although it really does depend on the weapon (I mean LS, not all weapons). Some paths have good raw and less status, some favore more status over raw. LS as a whole favors raw damage and sharpness over pretty much everything else due to its spirit combo mechanic.
Also, why on earth do greatswords even have versions that inflict status effects? How the hell are you going to ever inflict poison with a greatsword that does less poison per hit than a SnS?
afaik GS didn't even inflict status when you used a charged attack in the old games. This has been only just now fixed in MH4U. Previously it was useless, now it's apparently somewhat decent, but you'll still be better off with high raw and good sharpness.