How could they miss the export sharpening bug?
Guess you've never been involved in software development, right? Fixing one bug can introduce other bugs...bugs not seen before nor expected. That's what happened here. And, it wasn't just Lightroom that got hit with this bug, it also was introduced in Camera Raw 8.1. So, it wasn't really a LR bug it was a LR/ACR raw processing pipeline bug that got introduced in the last several builds that sadly, none of the internal testers caught. Was it a bad bug? You bet...was it "incompetence", to a degree, yes...some code was changed that introduced this new bug and nobody caught it. Was it "disregard for their customers"? You gotta be shyting me...do you honestly think so little of Adobe that this possibility is real in your mind? Or, are you simply trying to spread fear, uncertainty and doubt (FUD).
Look, it's ok to talk about what could have been done in LR5 or what should have been done in LR5 and what may be done in the future (LR6), but pulling this kind of crap out of thin air helps nobody...
I'm sure the engineers that modified the code and caused this bug are busy trying to fix it...is it a "data loss" bug? Nope...but yes, it's a problem but one that can be worked around...is Adobe embarrassed by this bug? You bet...nobody in their right mind however, would say that this bug would be a result of "disregard for their customers".
So, the work around isn't "convenient" but is it a reason not to use LR5? Nope...it simply modifies the way you need to use it. And it impacts not only LR5 but ACR 8.1 as well. So, until the bug is fixed, don't downsample images to less that 1/3 of the original capture size in Export...