Did you even read the article? It was specifying UNSCRUPULOUS painters! And, by the way, the photo at the top was not identified at all. How would anyone know whether it was done by a homeowner or not? Also did you ever stop to think that if a consumer has the knowlege to spot a dishonest contractor then by default he also has the knowlege to identify an honest one as well? And, pardon me, but just because you've never seen something has absolutely nothing to do with whether it has actually happened to someone else. Why would any honest business person be so defensive about the publishing of such useful information? If any painters/painting contractors object to a consumer having this kind of information maybe they are the dishonest ones!
More recently, professional painters are responsible for all preparation prior to painting. All scraping, sanding, wallpaper removal, caulking, drywall or wood repair, patching, stain removal, filling nail holes or any defects with plaster or putty, cleaning, taping, preparation and priming are considered to be done by the professional contracted painter.
A thorough scrubbing is a must before painting any exterior surface. It removes the dirt and broken-down paint residues that keep fresh coats from adhering and gets rid of mildew that grows on paint in all but the most arid climates. Most contractors clean with pressure washers, but in the hands of someone unfamiliar with the equipment, these can gouge wood, shatter glass, and drive water behind siding and trim. Using a hose, a pump sprayer, and a scrub brush is slower but safer, and just as effective.
Maybe you've just moved into a new home, and you haven't got around to buying brushes and rollers yet. Perhaps you're worried that your brush-skills aren't that good, and you won't achieve that professional-looking finish that you’re really going for. Handy professionals will turn up with everything they need to get the job done, from ladders and brushes, to rollers and tarps. You just have to provide the interior paint and primer!