They should without doubt have been able to get two better options than Mignolet and Karius. I think as much as anything stubbornness of both Rodgers and Klopp, insisting they could see something in their men everyone else was missing, has stood in the way of them addressing this issue.
However I think there is also truth in this:
think Reina won the golden gloves during his time at the club...that had a lot to do with Rafa's tactical approach though
very good shot stopper who usually made 3 or 4 high profile mistakes a season
Reina is head and shoulders above their current options but he played behind a properly competent and drilled defensive unit. On the other hand Mignolet can't do right for doing wrong, partly because of glaring deficiencies in his game, but partly because his nerves and confidence must be shredded playing behind that defensive six. Can and Wijnaldum let a ridiculous amount of midfield runners through, the back four looks poorly drilled, the fullbacks struggle to stop crosses and the centre backs are making poor errors. It truly must be a nightmare for any keeper to play behind that, let alone two who are clearly not up to the job.
Liverpool's keeping issue is similar to ours between Schmeichel and VdS but what's going on further in front of their net is as much of an issue as who is between the stick in my opinion.