Mr Trump is not very wrong. What about the judge who wanted to call back airplanes with cruel criminals of Venezuelan cartel members?
Judges should judge with a fully unbiased attitude, whereas for example here in Italy there are activist judges who are affiliated to determined parties and who regularly rule against the government's decisions on illegal immigration.
If the situation is the same or similar in the USA, I cannot blame the POTUS for his wanting to impeach judges. At least, some judges. On other occasions, the POTUS may be wrong. But judges are not representatives of the people for political decisions.
I do believe this is a very important subject. Why did we put this whole constitutional process into place in the first place? It is a check and balance system to dethrone kings and queens who assumed a divine position appointed or assumed by those seeing themselves above the law and divinely ordained. Judges while making decisions that are not always correct are given their positions because of their impartiality. Should we begin to go back to the dark ages of kings and queens czars and emperors as it appears you have suggested?