Yes that dogma was very confusing to me when I was trying to choose my roses, because there was so much information that it, including the subjective parts of it, tended to blur together into general impressions that were not necessarily apt for my own tastes and/or planned use and position of a given rose. I had to work quite hard to overcome those biases by taking reams of notes, some textual and some in the form of big charts with a row for each rose adn columns for criteria like colour, scent, vigour, health, light/shade preference, habit, leaf colour etc. In this way I think I made as far as possible my OWN choices, based on my own preferences. Still inevitably I'm sure some writers' opinions will have swayed me [whether to believe or contrarily to rebel], as I had zero physical experience with any of the roses I was trying to select. I was panicking actually, because I was trying to resolve the unresolvable. Though it was really exciting too. To have the roses in and growing is heaven compared to that period of uncertainly and garden upheaval. Next garden bed plan will be a more relaxed undertaking now that I know a bit more. I've come across roses that aren't even mentioned in some books or that get little more than a passing mention and no picture, that are completely beautiful. They seem to me extraordinary, but maybe yet others will come along [or rather stay put while I come to them :)] that the books will have very strongly opined were Great.
And about classification/provenance; yes it'll be extremely interesting when DNA data comes through!