not *wrong* - but if it doesn't work as good as the command line version (or at all in this case) what's the point? If you want a graphical front-end for nmap, write one...
Okay, first off the entire point is that someone may still prefer gui functionality to a command line. End of story, based on per-user preference, and out of your area to decide for everyone.

Second, I never said I wanted a graphical front-end. Not once. I was defending the person on this thread (who was negged for it) that enjoyed the GUI moreso than the command line. It isn't a matter of difficulty, it isn't a matter of "omfgwtfbbq which is better?!". It's a matter of what each user prefers the most. Firefox can't pipe pages directly to a text file or preform per-page searching for pipe cataloging and grepping, so should we say Firefox isn't as "good" as lynx? Hell no. You enjoy Firefox, some enjoy lynx regardless of the differences in functionality.

Let sleeping dogs lie and let others enjoy a gui if they want, without someone breathing down their neck.