Brees is certainly the outlier on the list (and Manning to a lesser extent), but it's also worth noting that he has thrown almost 500 more passes than anyone else, 750 more than Romo.
My take away from this as it relates to Romo was that it's certainly not inaccurate to say that he makes the big, game altering, mistake rather frequently. And yes, if he had some big time successes to balance it against like Brees and Manning, no one would care - but he doesn't.
And Schaub is just terrible.