...So Nodoka stabbed Shampoo.  She looked around at everyone staring 
at her.  "What?  She said she wanted us to give her the sword!"

Because this was a weak fic with unbelievable characterisation
and plot, it was a weak argument.  Shampoo is not a coward.  Ranma
is not a sniveling weakling who.  It is not plausible that Shampoo would
refuse to marry Ranma even if she really hated him, and it is even less
plausible that Cologne would approve of Shampoo's failure to live by 
Amazon Code.  Oh, and if Shampoo won, Ranma is now unconscious and 
therefore shouldn't be snivelling so much.  

Apparently it was written just to get around the "no character debate"
restriction.  

We've heard this old song from you before and it is no more convincing
now than it ever was.  In fact it was in discussion with you that I
became convinced that Shampoo was responsible for her own problems, when
you pointed out that she probably didn't have to give the kiss of death
in the first place.  

But that's beside the point. 

You give a list of reasons why people might have a low opinion of
Shampoo, some of which were nothing more than idle insults.  However, 
one of them caught my attention and that's the suggestion that Shampoo
may be thought of poorly because of her portrayal in the fanfics of good 
authors.  If that's the case then the answer is to write a good fanfic
supporting her cause, one in which she and Ranma are recognisable, and 
which contains a good story as plausible as...say Akane as an abusive 
spouse in "The Bitter End".  Don't lecture us, write a real story.