Despisers of specialization oppose it to a golden age when to be a thinker was to be a generalist, universalist, polymath, omnifarium doctus, a Renaissance man (whether or not they have the Renaissance in mind). Defenders of specialization sadly acknowledge the loss, but call it a trade-off: because we know vastly more than our predecessors, we are doomed to specialize: knowledge has become too complex for generalists to exist.
But both these positions are based on false comparison.
Between modern and premodern science, we err to compare the most difficult problems we can solve, and projects we can undertake, with the most difficult problems and projects possible to our forebears. If we compare their methods with ours in the same applications, we find that (for example) the Scholastic philosopher, weaving new Aristotelian riddles to account for every problem a modern physicist dispatches with a fillip of calculus, lived in a vastly more complicated universe than we do.
The diversity of our specializations and the complexity of our investigations are possible only because the leading ideas of science are now simpler than they have ever been before—subtler rather than easier, but simpler, because entities are fewer. Newton uniting the celestial and the sublunary, Dalton reducing a handbook of elemental behaviors to a calculus of atomic weights, Darwin tracing back the origin of species, Einstein folding space into time and time into space, Faraday's fields, Shannons's bits, Noether's symmetries, Feynman's diagrams, all bear witness. The scientific endeavors of the present are the most complex ever, because they are the least burdened with overhead.
The same movement, though by different means, is present in the humanities. Consider the half-facetious "Godwin's Law": "If you are the first to mention the Nazis, you lose the argument." But the warning of Nazism really does prune our thinking, mostly before we even speak. Knowing that certain ways of thinking can only end in horror saves us time wasted in toying with them, and effort wasted in arguing ourselves or others out of them.
The highest thinking takes place in this kind of shorthand. Philosophy, for example, would be impossible without the ability to reference positions by the names of their originators. Even Plato did it, with Parmenides, Empedocles, Heraclitus, &c. If we had to begin every discussion with a clean slate, it would be impossible to think at a philosophical level. Each such new name nucleates the floating notions and inchoate ideas that were not so much inaccessible before, as too much trouble to chase down.
Look at an orchestra. Hundreds of instruments, each with players who have traded much of their lives for mastery. Then look at a chamber ensemble from two or three centuries before. Compare an orchestral score with a piece of chamber music. What has changed? Has music theory become so complex that an orchestra full of instrumentalists is now required to instantiate it?
To the contrary: music theory has become simpler. Composers use chords (or tone rows) instead of counterpoint; but more importantly, tuning has been simplified. The system of tuning now in almost universal use—equal temperament—is the simplest ever: divide the octave into 12 exactly equal parts. Tuning used o be higher math; now it is A=440. Indeed, it could never be done with precision; thus the chamber ensemble had to be small enough that each player could hear, and adjust to, the deviations of others. It is only by the very simplicity of equal temperament that massed instruments can play in tune.
The very subtlety of our specializations, the very complexity of our problems and projects, testify that our intellectual progress has been due to the generalization of our ideas. It is because we increasingly speak the same language that we are free to develop dialects.
Even for orchestras, tuning only matters when there is something to play. What of composers and conductors? What of generalists? Where are they in the war of department against department?
If departments fight, then they have something to fight over, which implies there are still generalists around, however informally. If so, then their position in our society is like that of homemakers: so indispensable that they go unnoticed, so invaluable that they are not valued.