Nowadays it just seems the norm. I guess to keep things "Fresh & Interesting", but all it does is keep stories & characters from developing.
Rosenberg's Uncanny is doing great from what he says. And Bunn's Uncanny was cancelled at 19, even thought it was still in the solid numbers at that point. The estimates for issue 19 said the numbers were 33,318, which some books peak at, but that was the decline after 19 issues and a lot of editorial story hijacking.
Meanwhile books like Weapon X stick around until the sales hit 18,045.
Of course the estimates aren't official and don't take many things into account, but that's all we have to go on. So assuming the numbers are similar or somewhat close far as status.