They have not cared for what the world said, but they have cared for their art.
There are certain limits to individual capriciousness in style, long since laid down, as it were, by Beauty herself; which, transgressed, lessen, injure or lose beauty; and Browning continually transgressed those limits.
Again, clearness is one of the first elements in style, and on poetry attaining clearness, depends, in great measure, its enduringness in the future.

So far as clearness carries him, Tennyson's poetry is sure to last.

So far as Browning's obscurity goes, his poetry will not last like Tennyson's.

It is all very well for his students to say that he is not obscure; he is.

Nor is it by any exceptional depth of thought or by any specially profound analysis of the soul that Browning is obscure.