I am pretty sure that they weren't in the top 20 that often before Helfrich got there. Going back on Rivals, they have been pretty much the same going from Kelly to Helfrich (20s). Looking at the 2017 class right after they fired their coach doesn't make much sense.Oregon recruiting has been trending down the past couple of years. Rivals has had them in the top 20 once since Helfrich took over. Their in the low 40's right now. Given how much they've spent on facilities for that program that isn't good enough.
Maybe Helfrich is not the answer but there is enough young talent on Oregon that I agree with @Buffnik that this seems like an overreaction. I guess it all depends on who they get. If they make a meh hire, I could see this really hurting them.