This article is from the Triathlon FAQ, by with numerous contributions by James Goddard others.
Drafting is a hot topic of debate among triathletes.
Those that are against drafting often list the following reasons:
Drafting takes away from the individual competitor nature of the
sport. Drafting is less safe/causes higher insurance rates.
Those that are for drafting often list the following reasons:
Drafting evens out triathlons which often are weighed to longer times
in the bike leg. Drafting is more spectator friendly.