Even when it was first released, 'The Dunciad' was not a poem which was received positively by everyone. It was, and still remains, very controversial. Some critics have noted that changing moral norms and changing historical circumstances have further enfeebled the poem's relevance nowadays.
Granted, 'The Dunciad' is very hard to understand. I usually do not like to skip the footnotes, but in this case it is not a matter of opinion, they are essential. Ironically, I have spent more time reading the footnotes than the actual poem itself. However, I have come to appreciate that it is only by such an awareness of these real personalities does the poem retain its comic tension. Furthermore, 'The Dunciad' reflects a certain Augustan tradition and attitude which is rooted deep in the classical past, so a background reading is recommended.
What really redeems 'The Dunciad' from mediocrity or oblivion, especially nowadays, is its general tendency to focus on an idea of 'eternal interest', as personified by Queen Dulness and her vast army. Personally I think that Book Four by far the masterpiece of the whole composition, reflecting a certain degeneration of the literary spirit that is unfortunately comparable to nowadays. Pope foresaw a particular perversion of moral ideas that has since become a reality. However, 'The Dunciad' should not be misunderstood to be pessimistic. It was the aim for a satirist to emphasize chaos, all that is negative in life and humankind, as being triumphant in the end; "Universal Darkness buries all".
This is deliberate, and I daresay effective. By depicting the rise of bad taste, dulness and folly in society, the satirist is laying bare his own personal convictions and moral standards. Pope was a little negative in this regard, I think, but that does not mean that he was not right in his writing 'The Dunciad'. If only more people took such an interest in the contemporary affairs and personalities of these times, we would not be in the position we are in. The Queen of Dulness is constantly gaining territory, even as we speak.
DeQuincey had described 'The Dunciad' as "a monument of satirical power". I would not say that it is better than, say, 'The Rape of the Lock', but it still remains one of the most imaginative, unfortunately almost prophetic as well, and effective compositions of the eighteenth century, possibly of the human history.