If I could ban one type of writing or speechmaking, I think my choice would be simple. I would do away with the "why I lost" message. Brad Carson, who lost his Senate race to Republican Tom Coburn has a column on that topic up at New Republic (subscription required). Former Georgia governor Roy Barnes still glories in the reason for his loss back in 2002. The "official" reason for his defeat was that he took the Confederate-style state flag off the capitol dome and replaced it with something less offensive. Better reasons would be that he governed dictatorially, presided over some really bitter redistricting (not covered by the national press because Republicans were getting nailed), pissed off the teacher's unions (which I liked), and was running in the same party as Max Cleland. He won a Profiles in Courage Award for giving up his seat as a consequence of changing the flag.
Then again, maybe those "why I lost" speeches and columns aren't so bad. I'd certainly rather have Roy Barnes and Brad Carson justifying themselves in courageous defeat than standing in the well at the state or federal capitol justifying legislation.