Really? We're still arguing over this? Man, I knew mirrors was a polarizing issue, but more of a style argument than anything else. To each his own, but IMHO (emphasis mine) I find mirrors very useful.
Two intractable positions:
"Using mirrors is absolutely safer than not using them." (note global statement - applies to all riders, all situations).
vs
"I have been able to ride perfectly safely without them in all the riding I've ever done, and therefore have never had a need for them nor do I think that if I were to use them I would be absolutely safer than not." (note individual statement - applies only to the writer and only the situations she/he has ridden in)
Neither side believes the other and both are intractable. But only one thinks their opinion applies to others of whom they have no personal knowledge.
Style has nothing to do with it.