<lots of good and valid reasons elided>
The problem with all your reasons is that they have an underlying assumption
that people have enough clue to realize things like "they don't need it",
or "they don't need more than one or two". I'm however convinced that for
each network admin out there who understands there's times to run WINS and
times not to use it, there's at least 5 or 10 who said "ooh shiny" and clicked
on the button to install it...
And remember that those sheep can't say "firewall".. ;)