I've now played the event long enough to have earned all of the emblems, and purchased most of the rewards. I say this not to brag, but only to demonstrate that I've been playing the event for an appreciable period of time. It's been enjoyable, although a certain amount of rinse-and-repeat is probably unavoidable. So here's my .02, FWIW.
The only Shedu drop I've gotten is a barrel, and that fell into my lap in the opening hours of the event; nothing in the days since since, and I've killed at least my share of Simbolists. I've been asking in my mission groups, and so far only one other player reported receiving any drops, and he only got two of the parts. Yes, I understand RNG, and I know this is the way RNG works, and there's nothing unusual about these drop rates. I get it. But grind isn't just about the maths; there are other aspects at play.
Based on what I've read, like the Embolist before it, the Shedu looks to be not worth the amount of grinding it will take to obtain one, at least from an effort/reward standpoint. And I suspect that DE would not want WF to earn the rep of a game whose hardest drops are a waste of time. Seems like the simplest solutions would be to either make the Shedu worth the effort (and thus risk power creep), or conversely leave it as it is but bump up the drop rates somewhat, at least to the point where assembling the weapon seem achievable. Among the players I've been speaking with, most don't seem to feel that it is. Most don't seem to care about it. (A third, less desirable option would be to simply not include weapons/sparklies in the first place that most players will never bother working for.)
At the point in the event where I am now, I'd like a reason to continue participating, but as long as DE keeps making the Shedu parts out of Unobtainium, there's not enough of a reason to grind for them. As I said, just my .02.