What is the purpose of "A Modest Proposal?" What is Swift trying to reform? Does he go too far in this essay?

The issue of whether or not Swift goes too far in "A
Modest Proposal," is an issue of taste.  It's a satire, of course, so the speaker has
much freedom in what he writes.  He also uses irony.  Both satire and irony often use
exaggeration as tools to accomplish their purposes.  So, again, the writer has a great
deal of freedom to work with.

The question is, though, even
within the accepted norms of satire and irony, whether or not what Swift does is in bad
taste.  His proposal and his descriptions, etc., are certainly grotesque, and his
central idea strikes at the core of
humanity--cannibalism. 

Ultimately, however, though the
essay probably is in bad taste, Swift decides that using bad taste is worth the risk. 
The essay shocks the reader, and probably would not have done so if it weren't in
bad taste.  The bad taste of the proposal is part of the
point.

In the end, each reader probably decides whether the
essay is in bad taste, whether it goes too far.  I love the wit and the humor and the
satire and the irony.  But that doesn't mean another person wouldn't find the essay in
bad taste.