more weapons with evolutionary "stories" would be music to my ears, as well as upgrade bounties (brilliant idea). I don't even have a Husk of the Pit yet- don't care about the Necrochasm at all, outside of collection, but if the exotic at the end were some kind of wild hand cannon, scout, fusion, or machine gun I'd be going insane doing everything in my power to work toward it.
Yeah--unlike someone on here who shall remain <sarc>Nami-less</sarc> who farmed 12 hours for the Husk, it just happened to drop twice for me just doing regular missions and bounties.
Once I got it, I went on the journey to upgrade it to the Ally. I thought it to be a fun idea eventhough the Ally turned out to be under-whelming. I'll never forget two-manning Urzok with a stranger-Guardian for the first time! We got him, but boy--what a memorable fight. And like you, I won't be farming Crota for the Crux--if it drops, awesome. If not, meh.
As for the "Weapon Bounty" mechanic, I like that you usually have a choice as to which one you did--usually one of two or three from Xander. I didn't like the mixing of PvE and PvP requirements for some of them though, but other than the Invective (still in my inventory after over two months), I managed to complete the others with some help. Maybe they should give people the option to choose a PvE or PvP path for each weapon bounty?