No argument needed. If you were able to achieve a final good quality recording with an usb microphone, that's great! I guess it all depends with what your doing with the recording once your done.
Now if your getting good results with a usb microphone -you should scourer this forum and explain to the hundreds of people who are in need of help using an usb microphone. 99% are saying that their recordings are not what they are wanting or expecting when it comes to quality recordings that they can brag about.