How well the paint stands up on the tile is almost entirely dependant on how hard a film it forms. The softer the film, the more quickly it's going to start looking dirty from all the dirt embedded in it by the force of people's foot falls. The harder the film, the less dirt will become embedded in it, and the longer it will remain looking new and the slower that appearance will deteriorate.
If you use a water based floor paint, then I couldn't agree with Noseall more. however, if you use a proper oil based FLOOR paint, then you should get good service from it.
Every paint company will use the paint it has that dries to the hardest film to make floor paints from. This is the reason why epoxy based floor paints are the standard for concrete factory or warehouse floors. For residential floors, oil based paints like alkyds and polyurethanes are more popular because they're more user friendly. A polyurethane hardwood floor finish is really nothing more than a polyurethane floor paint without any pigments in it to give it color and opacity. It's the difference in hardness between a polyurethane hardwood floor finishcoating and a water based paint that explains why most people are happy with the durability of the polyurethane on their hardwood floors, but Noseall says that floor paints start to look shoddy real quick. Noseall probably used an emulsion floor paint which dries to a much softer film than a polyurethane floor paint would.
The reason why companies are selling emulsion floor paints aren't because they provide good service on a floor. It's because increasingly strict environmental legislation requires that the paint they sell contain smaller and smaller amounts of VOC (volatile organic compounds), and emulsion paints typically contain less than 10% VOC's, where an oil based paint will likely be over 40% VOCs. So, you gotta use a emulsion paint to keep the environmentalists happy and the air clean.