The general idea is for them to cover as many models as possible per type of sparkplug. They are willing to take the risk that no damage will be done. Obviously they won't recommend a plug that will cause direct damage (impact with the piston for example), but other than that, if they think thay can convince enough folks to buy "triple gold plated, platinum tip, rhoedendrum core, solar influx capacitor equipped with mother-of-pearl insulators" spark plugs to make a profit, they will do it.
Bosch makes great spark plugs, but they have a marketing dept. just like the rest of them. Stick with the plain ol' "Super" and you'll be better off.