I kinda
already touched upon this before, but I just want to point out that it all started with Chapter 197 when Kubo devoted nearly an entire chapter on Arrancar exposition (well actually it was more like half, since he wasted the other half on pointless comedy) and named the chapter
"Approaching Danger". I don't see how anyone can seriously read that entire chapter and say that Kubo isn't making the arrancar's out to be a serious threat...