The magisterium is infallible not because it is impersonal, but because Christ guaranteed that when certain people teach under certain conditions, they are protected from teaching error.
You offer only more confusion, needlessly.
The Magisterium is infallible because it was instituted by Christ - that is what pope Leo correctly and literally said, the theology manuals you read should say that exact same thing or you're reading the wrong ones. The magisterium is guaranteed free from error because Christ instituted it. It's not complicated Mith - just read the blurb from pope Leo I posted.
Christ guaranteed ONLY the pope infallibility under certain conditions - read the decrees of the First Vatican Council. No one but the pope is guaranteed protection from the possibility of error - and then ONLY when teaching certain doctrines under certain conditions.
The view proposed by stubborn is not only theologically untenable, it is philosophically untenable. The Catholic faith in its entirety is a series of propositions. That we are aware that any of them even exist, never mind whether or not any of them are even true, is owed to the fact that Christ's institution of the apostolic college and the Petrine office (all living, authoratative, and permanent) propose them to us for belief. But the propositions themselves are not living. Only things with a soul live. To say that a teaching lives is incoherent. Teachers live, not teachings.
What view of mine? I am referencing Pope Leo XIII, literally. That the teaching, the magisterium, are living teachings means it is always tenable, always pertinent, always true, always there to enlighten. That which is permanent can only be living.
From the First Vatican Council, here's a new one for you - Divine Magisterium = Christ teachings:
Everybody knows that those heresies, condemned by the fathers of Trent, which rejected the
divine magisterium of the church and allowed religious questions to be a matter for the judgment of each individual, have gradually collapsed into a multiplicity of sects, either at variance or in agreement with one another; and by this means a good many people have had all faith in Christ destroyed.
Also
Wherefore, by divine and catholic faith all those things are to be believed which are contained in the word of God as found in scripture and tradition,and which are proposed by the church as matters to be believed as divinely revealed, whether by her solemn judgment or
in her ordinary [magisterium]
and universal magisterium.