How do you come to that conclusion?
First management job (UE Figueres): in charge for 9 games, fired after relegation, went back to youth coaching
Then (Espanyol reserves): in charge for 7 games, fired, club relegated, went back to being an assistant elsewhere
Then (Halmstads BK): club finished last, relegated, Clotet left and went back to coaching
Then (Malaga reserves): lasted one season, left, went to 'academy consultant' then assistant at Swansea.
Then (us): record home defeat, beaten twice by the leagues whipping boys, signed a whole load of rotten players, fired, went back to being an assistant again.
There is a pattern there! Gets a management job, fails - goes back to being an assistant or coach somewhere, quite often with someone he has worked with before. That seems to say that he in fact IS a terrible manager, but probably quite a decent assistant or coach if he is asked to implement someone else's ideas. There's no shame in that; not everyone can be a chief, you need indians as well (is that racist?). It's just a shame that we had to be the club to finally cement that fact.